The best budget sampler I've ever used is the Roland SP-505. You can sample, edit, effect, sequence. The big plus is that it's not a beasty table top unit; only about the size of a text book. The only downside is finding a 128mb smartmedia card, but if you're savvy enough you can generally find one for a few bucks. I regularly hunt thrift stores and check out old digital cameras, occasionally you can find one for a couple bucks with a memory card inside. The machine itself generally runs you about $150-$200 used.
There are a few other units out there that I"ve played with that are good, but take up WAY too much space. The ASR-X is a classic, but has limited sample capacity. The Roland SP-808EX is a hefty unit, but again pretty big and uses a noisy Zip250 drive.