There has to be a way to make your own voltmeter. I know I have seen it done before.
I have a very nice one that cost me $90 (US), and it does everything I need it to. Only problem is that it is more than most people would like to spend. I know you can find one for around $20, but I wouldn't gauruntee they will work well.
I"m going to do some research on making your own VOM and post back.