I buy what I like as well. But, let's face it. A collectible with a lower edition size has more collectibility then one with a large one. Besides, I don't like paying full retail for a piece with a large edition size, when it'll turn up later on, on eBay or whatever for considerably less.
I don't buy my collectibles for the collectibility either. I buy it because I like it. If it has a "collectibility" factor to it then thats fine. Honestly, there are pieces like the SW VCD figures or Galactic Heroes that I buy that I think a lot of peple would say don't have the collectibility, but I get them anyways. Most items now a days go down. There are fewer items that go straight up in price than when the SSW statues where king. I buy it when it goes up and if it goes down it sucks but I'm buying mine now and whatever happens/happens.