I just bought a 2000 Oldsmobile Alero 2 days ago, and when I start it there is a loud squeak that lasts maybe 15 seconds. Unfortunately I bought the car 'as is'. Will it most likely be a belt, and if so, how much would it cost me for the belt itself and how much work is involved? This totally sucks but I guess that's the reality of buying a car 'as is'. Then yesterday, the car would not start - it took 4 tries and I had to press on the gas. Its been fine since.
A squeak like that is almost certainly a slipping belt. The easiest fix would be to pick up some "belt conditioner" spray from an auto parts store and spray it on the inside of all your belts, and see if the problem goes away. If not you can try tightening the belt that's causing the squeak; this is not too difficult, and just involves loosening a couple bolts so you can adjust the component with the pulley (alternator, compressor, power steering pump, etc.) then tightening them back down while putting tension on the belt. If the problem persists you'll need to replace the belt.