I'd suggest a 12" 45rpm record with 10 mins per side for the best loudness and quality. Pressing costs almost nothing, just a few bucks per record. It's getting the masters cut that costs.
To get the masters cut, you're looking at about $500-$1000.
You can save by getting a 7" disc cut, but even at 33rpm you're only going to get a maximum of 8mins per side and at 7" 33rpm, anything longer than 5 mins per side sounds really lo-fi.
7" masters are usually about 2/3rds the cost of 12".
Oh, and watch out for sharks overseas who say they can press and ship it to you for nix... Vinyl has ridiculous import taxes on it unless it's a floor covering, at least it does in this country (Australia). Also, I've heard stories from people who have had records made in "bloc" type places in Europe and they suck.