This toy is what we call an "error". Some people treat them like rarities while others consider them dumb mistakes. I remember reading Steve Sansweet's replies to people's letters in old Star Wars Insider magazines. They would ask if an error increased the value of their collectible or not. Sansweet would reply saying that an error usually reduces the value of a collectible, and he even told someone to try returning the toy and get a refund! To me, they highly increase the value because they make the figure strange and intriguing. Seriously, this Luke figure may be my favorite officially licensed collectible that I own.
Normally, this would be a Canadian, red card, POTF2 (or "LE POUVOIR DE LA FORCE") Luke Skywalker figure. Missing its saber, though, makes it something far more special in my eyes.