With the economy the way it is, I'm trying very hard to stay within the confines of my Stash -- both Fabric & Fiber -- in order to save $$$.
Staying within the Fabric Stash is easy, because I have an entire garage wall full of fabric with which to play, garnered by years of hoarding and purchasing (although in fairness half of the fabric belongs to DH).
Staying within my Fiber Stash is a bit more difficult, because I've tried to contain the yarn to one 32-gallon Rubbermaid bin, and the unspun fiber to a bin half that size. Plus I've only been actively knitting & spinning for less than a year. So I haven't had much of a chance to increase the Fiber Stash as much as the Fabric Stashes. But my LYS is such a place of temptations, plus everyone seems to be having really good sales on fiber/yarn.
And I think, "Wow, that's a good price!"
But even with a good price, you're still spending money ($$$) no matter "how" much you save from the full retail price. And spending money means you're not actually saving any money at all.
I've mentioned my Backlog of Fiber before, which should keep me busy for at least several months without needing to buy additions to the Stash, so says the Logical & Practical part of me. But, that doesn't stop my inner ferret from looking at all the pretty pretty yarn/fiber and squeaking, "PRETTY SHINY!"