I tend to only buy omething that I need for a specific picture, and only if I cant be bothered modelling it myself. I also consider how often I could use it in other pics. I tend to look more at the quality of the textures for props. Price is a consideration and I am willing to pay more for a nice piece with good textures and its something I can use a lot.

Over $10 and I need a very good reason to buy.