Actually, one of my Golden Rules of Collecting is, "If you see it, and want it, buy it!"
I have heard too many stories about people passing on figures initially, and then having a hard time finding them. Years ago, I found the POTF2 wave with the Death Star Trooper and ReeYees in a little mom and pop store. I figured, "if this store has them, they will be everywhere". But being the SW nut I am, I bought the whole wave. Only later did I find out it was cancelled.
I do, however, place patience high on the list of collector traits. I look for figures in stores for about 6-8 months before I go to ANY kind of seconday market or toy dealer. The truth is, most things show up sooner or later. During Saga, I couldn't find a Mace Windu lollipop figure at all. I really gave up. One day, close to a year later, I was in a Duane Read drugstore, and there he was!