I find myself buying many titles because of a good sale that I otherwise would have skipped.
I see where you're coming from though. It sucks when you put your heart and soul into something, and then you gently release it out into the world like a smiling parent only to then watch it be mauled by a cruel and unforgiving world.
The fact of the matter is there are so many great indie games out there, and only so many gaming hours in a day and so little money in my wallet.
* Stuff I buy on sale because it looks ok and at that price it's nice. That makes up 90% of my library
* Stuff I buy right at release because I want it now because it looks/feels/seems that awesome. Recent examples in that category are Binding of Isaac and Bastion, which I bought at release.
But I tend to buy indie games at launch more often than "big name" $60 stuff.