Are there any good international volunteer programs for an undergrad that cost less than 2K?

I'm looking for some volunteer experience (it doesn't matter in what really) in other countries besides the US (South America, Africa, New Zealand, etc.). I'm an undergrad student who doesn't have much money. Most programs I've found cost a lot of money for a short of period of time. There has to be something out there that costs less than a couple thousand (not including airfare) and that lasts longer than a week. Any suggestions?