I'm with Wade on the used tool side of the equation.....some of my best finds are garage sales, flea markets, antique stores, second hand shops.
I have a chisel in my roll that I paid 25 cents for, it's an un-branded socket chisel that was rode hard and put away wet. With a little work and attention I was able to transform it into a very sharp chisel, replaced the handle and I use it all the time.
I am fortunate to live within a 20 minute drive from the Log Cabin Shop and quite often old chisels, planes, scrapers and peices parts show up. Wasn't long ago that somebody dropped of a very large lot of old hand vises that were very reasonable.....ended up with a couple. I'm in competition with a buddy of mine to see who can find and secure the best finds at the cheapest cost from the Log Cabin, I think I was leading for a while, but recently he has found some real winners and I think he has overtaken me.
As Mike said, you really don't need a bunch of chisels, but rather 4 maybe 5 at the least.