Originally Posted by: snojonesI am looking at attending a crafts fair and I want to be able to play a bass through a battery powered amp. Are there any such amps that don't cost a fortune?[/QUOTE]
This is an inexpensive option.

http://www.amazon.com/AC1RVBASS-Miniature-Battery-Powered-Amplifier/dp/B0056QRGBE
[QUOTE=snojones]Is is ok to play a bass through a regular guitar amp?

It's not a great idea, but it can be done at lower volumes as long as you aren't pushing the speaker too hard. But I wouldn't recommend it as you damage the guitar amp.

Hope this helps!