It doesn't have to be some rarity or an amazing bargain, it could be something as simple as a mainline figure that you just absolutely love and are happy about picking up. I would say the best purchase I made was when I was at a toy show, I snagged a MISB (japanese) G1 Starscream. The box is actually in pretty good condition too. Albeit I passed up a MISB G1 Megs for him (can't recall how much he was at the moment though), but SS is my favorite TF ever so it was worth it. I think I got him for 80...was a while back though.