I own only 5 stautes, with a 6th on the way and 4 more on pre-order. I tend to buy based on images seen on the web.
3 factors decided if I buy:
1. Size - I prefer 1/4 (although I have a smaller statue on pre-order)
2. Price. If the price is too high, then it's a no no.
3. If in my eyes the statue has a wow factor (for whatever reason) then this ultimately is the most important factor. I might buy 1 of a set with no intention of wanting to complete a set.
So far *all* my statues are for keeps