If I gave someone an old bag 'o barbies, and one turned out to be worth something, I don't think I'd want to know, because then I'd just kick myself for not checking first. If my SIL gave me a bag 'o barbies, and I suspected one was worth some $$, I'd probably hang onto it, because in 10 years, I could put any money I made off it into something for my kids, college, car, something... as long as the recipient of the value was the recipient of the gift.