I agree with the rest! Buy what you can afford, as you get more experience, you'll change what ever doesn't work for you any longer.
I used to look only at the price of fabric when I first started quilting,I never threw anything away; some of it didn't really make me happy while I was working with it, or it didn't perform how I thought it should after it was quilted... these days when I bump into something from my stash that is a poorer quality, I get rid of it.