Dan,
There is a lot going on inside a front projection CRT and retubing a CRT is thousands of dollars.
The things to watch out for:
1. Bad power supply
2. Incompatibility with signal types you want to send to it.
3. Burn in on tubes (there are good articles on tube burn in online)
4. Size/How will you mount.
5. Brightness
Now, with that said, you still probably will be pretty happy for 60 bucks. Many projectors have setup menus and guides to walk you through setting things up. Those that don't will have dials that need to be adjusted. This can be a major pain, but if you spend some time working with them, you will be able to dial the green back and the red and blue up some. Then you will have to converge and all that other fun stuff.
If the projector was 500 bucks and you were clueless - I would advise against it... But for 60 bucks? Do it!