The beauty of an auction is that you never know what amazing items might go under the hammer, and if you're lucky, you might even snap up a bargain! Unfortunately, you'd need some deep pockets to afford the items in this round-up.

From artwork that once belonged to music legend David Bowie to a seriously swanky European supercars, read on to discover the most valuable collections to have ever sold at auction. All dollar amounts are in US dollars.

Soccer star Pelé sold the biggest collection of football memorabilia in history in 2016. The Brazilian three-time World Cup winner auctioned off 2,000 items, including trophies, medals and personal items, with the entire lot fetching £3.6 million. In today's money, that's an impressive $5.4 million (£4.4m). 

The star of the show was a replica of the Jules Rimet Trophy, which was made for Pelé after the 1970 World Cup. It sold for £320,000, or around $483,500 (£390.6k) today. 

The late silver screen starlet Audrey Hepburn (pictured) is an icon, so it’s hardly surprising that when items from her personal collection went up for auction at Christie’s in 2017, they raked in some serious cash. Up for grabs were clothing from the famed fashionista’s wardrobe; memorabilia from her beloved films like Breakfast at Tiffany's and My Fair Lady; and portraits from Hepburn’s personal photography archive. In total, the collection fetched £4.6 million, which is around $6.4 million (£5.1m) today.

Among the lots was a gold lighter (pictured) from the Academy Award-winning classic My Fair Lady. It smashed its £3,000 to £5,000 estimate, raking in a whopping £20,000, or around $28,000 (£22.4k) today.

A collection of exceptional vintage timepieces sold for $6.1 million during a private watch sale at Sotheby’s New York in 2015, the equivalent of $7.5 million (£6m) today. The auction featured 22 Swiss enamelled watches crafted in the Industrial Revolution era, many of which had gone unseen for generations.

The top lot was a Singing Bird Scent Flask (pictured), which has been attributed to Swiss watchmakers Jacquez-Drot and Leschot of Geneva. The exquisite piece fetched a hefty $2.5 million, which is around $3 million (£2.4m) today.

In 2016, 702 items, including artwork, furniture, and jewellery belonging to former US President Ronald Reagan and his wife Nancy (pictured), went under the hammer at Christie’s. People were evidently eager to snap up a piece of US history, with a record level of bidders participating and 100% of the lots selling. In total, the sale raked in more than $7.2 million, which is $8.8 million (£7m) today.

The star seller was a patriotic diamond, sapphire, and ruby ring by Bulgari (pictured), which was worn by Nancy Reagan on July 4, 1986, for Liberty Weekend celebrations. It smashed its $5,000 to $8,000 estimate, fetching an impressive $319,500. In today's dollars, that's the equivalent of $389,900 (£312.6k).

It’s known that stamps are a popular collector's item, but the little pieces of paper can sell for almost unfathomable sums. Take, for example, when billionaire collector Bill Gross auctioned off stamps from his prized collection in 2018. The average selling price for a lot was $100,000, with the top selling 24-cent 1869 Pictorial Inverted Center fetching an incredible $750,000. In today’s money, that’s around $874,800 (£700.8k).

In total, the collection of 103 stamps raked in a stunning $10 million, with hundreds of bidders participating in the event. When inflation-adjusted, the collection fetched $11.7 million (£9.4m). 

Wine is a popular item that regularly features in auction house sales, but Sotheby’s New York had a very unexpected surprise when they sold billionaire Bill Koch’s collection of fine wines for a whopping $21.9 million in 2016. In today's money, that's around $26.7 million (£21.5m). 

The massive collection boasted over 20,000 bottles, with the highest selling lot being a crate of the acclaimed Chateau Mouton-Rothschild 1945. It sold for a hefty $343,000, which is around $424,300 (£342.1k) today. 

Over 400 artworks owned by legendary musician David Bowie went under the hammer in 2016. Auction house Sotheby’s were overwhelmed by sales figures, which were more than double the original estimates, reaching a total of £33 million. When adjusted for inflation, that's a chunky sum of $50 million (£40.2m). 

Artworks by the likes of Frank Auerbach, Jean-Michel Basquiat and Damien Hirst were up for grabs at the auction, which broke 56 sales records by its conclusion. And over 1,000 bidders participated, hoping to snap up some iconic music memorabilia.

A farmer from Wiltshire in England made headlines back in 2016 when he sold what is considered to be one of the most intact collections of Chinese ceramics in the world. Spanning 1,000 years of Chinese history, the collection of Song, Ming, and Qing porcelain fetched £45.8 million. In today's money, that's $69.4 million (£55.8m). 

The item that stole the show was a minuscule 15th-century white and blue Moonflask (pictured), which fetched £10.1 million. Adjusted for inflation, that's a healthy $15.3 million (£12.3m).

Who would have thought that coins could be worth $44.8 million? Baltimore banker Louis E. Eliasberg achieved that price when he sold his collection in 1997, setting the world record price. 

When adjusted for inflation, the coin collection sold for a staggering $81.4 million (£65.5m). The highest selling item was an 1804 silver dollar, which fetched a cool $1.8 million, or $3.3 million (£2.6m) today.

A range of luxury European supercars fetched a whopping $67 million at an auto auction in 2015, or around $82.9 million (£66.5m) today. Lamborghinis, Ferraris, and Porches were among the 25 classic cars featured in the swanky collection. 

The most notable car in the collection was the ‘Pope’s Ferrari’, which fetched over $6 million, or $7.2 million (£5.8m) today. The Ferrari was gifted to Pope John Paul II back in 2005, though he never drove it himself, opting instead to auction it for charity. 

Russian billionaire Victor Vekselberg bought the world’s largest collection of Fabergé Imperial Easter Eggs back in 2004. A rare and unique purchase, only 50 eggs were ever crafted, nine of which belong to the collection.

Among the collection was the stunning Coronation Egg (pictured), which Tsar Nicholas II of Russia gifted to his wife in 1897. Vekselberg snapped up the collection for an undisclosed sum, but pre-auction estimates were in the range of $80 million to $120 million. That’s an incredible $124.9 million (£100.5m) to $187.3 million (£150.8m) in today’s money.

Late screen starlet Elizabeth Taylor’s private jewellery collection (pictured) went under the hammer at Christie's auction house in 2011, smashing its pre-sale estimate of $20 million. The enviable bling collection achieved a much more sizeable $116 million, which is an eye-watering $152.3 million (£122m) today. 

Among the 80 items was Taylor’s infamous 33.19-carat diamond ring (pictured), which was gifted to her by Richard Burton. This iconic piece of history was snapped up by one lucky buyer for $8.8 million, which is $11.5 million (£9.2m) today.

The art world went into a frenzy in 2015 when Sotheby’s revealed that it would be selling its late director's private art collection. Though it just surpassed its sales targets, A. Alfred Taubman's (pictured) collection fetched over $377 million, making it one of the most prestigious collections of art works to sell at auction. 

When adjusted for inflation, the impressive collection achieved a jaw-dropping $466.4 million (£373.7m). It included works by iconic artists like Van Gogh, Giacometti, Picasso, De Kooning, Kandinsky, and Degas, proving that Taubman had a passion for the art world in and out of the auction house. 

Yves Saint Laurent will always be remembered as a notorious French designer, but very few are aware that the fashion mogul was one of the biggest art collectors of our time. When the late Laurent's art collection went under the hammer in 2009, it fetched a whopping 373.5 million euros, or around $540.4 million (£432.1m) today. 

Artworks once owned by billionaire real estate mogul Harry Macklowe and his ex-wife Linda, have recently become the most expensive art collection to ever sell at auction (not factoring in inflation), fetching an eye-watering $922.2 million (£739m) in total over the course of two sales. The seriously impressive collection featured pieces by some of the world’s most renowned artists, including Pablo Picasso, Andy Warhol, and Cy Twombly.

A New York State Supreme Court Judge ordered the feuding couple to sell 65 pieces of art from their shared collection and split the profit amidst their high-profile divorce proceedings. This untitled work by Cy Twombly (pictured) fetched almost $59 million (£47.3m) when it went under the hammer. 

A collection of 1,500 artworks and various other valuable items once owned by Peggy and David Rockefeller fetched $835.1 million at auction in 2018, a mammoth $974 million (£780.4m) when inflation-adjusted. The billionaire couple were famed philanthropists during their lifetime, and all proceeds were donated to various charitable causes, including education, the arts, scientific research and land conservation.

Included in the auction were works by world-famous artists like Picasso, Monet, and Matisse, with the star of the show being Piscasso’s Fillette à la corbeille fleurie. It achieved a whopping $115 million, which is $134.1 million (£107.4m) today.