When the G.I. Joe range was first dreamt up in the early 1960s, marketers worried that boys wouldn't want to play with dolls and, as a result, the phrase "action figure" was coined. G.I. Joe action figures have gone through several incarnations since then, meaning that if you have a rare or early doll that's still in good condition, it could be worth a lot.
In 2003, one of the prototype action figures was sold by Heritage Auctions for $200,000, which is the equivalent of around $343,000 (£270k) in today's money. More recently, rarer figures, such as the Marine pieces (similar in style to the one pictured), have fetched upwards of $550 (£432) on eBay.