As far as the kids are concerned, we got the two older kids' bunk beds on craigslist, as well several car and booster seats, almost all of their Thomas trains and tracks, and a boatload of clothes, to name just a few of our many purchases. We have been fortunate to receive a lot of the kids' clothes as hand-me-downs from friends and family, but we also have gotten several huge lots of clothes from people on craigslist, usually for a small percentage of what they would have cost new.
Hopefully this post won't cause you all to rush over to craigslist and buy up everything in sight. But, I would suggest you at least take a look the next time you are in the market for something. You may be glad you did.