I'm on a very tight budget. I'm also into very scrappy quilts thanks to Bonnie Hunter. What I've been doing lately is buying 1/4 to 1/3 yard pieces. It gives me the variety of strips I need for a project and adds to my stash plus gives me that happy feeling buying quilt fabric brings, lol. :-)
One thing I've learned over the years, however, is not to buy fabric simply because it seems like a good buy. I've got some OK stuff from at least 15 years ago that I thought I SHOULD buy because it was a good deal and I might use it someday. Seems rather obvious but when I was first getting started I thought I had to build this all encompassing stash. So my advice is start small, take your time, and have fun!