I agree with what others have said, and craigslist is a really good source for tools, if you take the time to educate yourself on what you are looking for, and make sure to check out condition before you buy. Always remember to buy the most tool you can afford, and NEED. If you are only going to use the saw for a few small projects, buy cheap. If you will use the saw for decades, then perhaps saving up for a more expensive saw, that you don't need to replace is the way to go. I found a used Delta unisaw, and only paid $600 for it. A unisaw is a really solid piece of machinery, but you aren't going to be moving that from place to place on a whim. There are 3 big things which will make a huuuge difference on what your saw will be capable of:
1) Tune it up. Take the time to make sure the saw is parallel to the fence, and perpendicular to the table surface. Spend a LOT of time doing this after you buy your saw (new or old)
2) How good the fence is will affect how happy you are with the saw. Beisemeyer is one of the best fences out there (I have one), but there are a bunch of knock offs available now that the patents have expired. A solid fence system will affect your cut. If the fence flexes, you can't make a straight cut. My father has a 50+ year old craftsman table saw. He recently replaced the fence and is much happier with it than he was with the original one.
3) A good blade. I have used a wide variety of blades, and a good sharp blade can make a nice cut. But after I used a Forrest blade, I never went back. My Forrest 40T(tooth) makes a better crosscut than any 80T Frued I ever had. They cost 2x, but seem to stay sharper 2x as long, and have waaayy bigger carbide, so will last longer.
Long post, hope it helps.