I rarely need/use my amp as I play mostly out of a PA. However, for those situations where I'm in a pinch, I managed to pick up a real budget amp, the Behringer ACX-450, for about half the cost new on a local craigslist transaction.
It does...OK...not thrilled by it, but it does it's job. It has two inputs so I can go guitar and vocal mic for a small venue. It also has some basic reverb and chorus effects with a footswitch.
For what I paid, I'm happy...but I wouldn't pay full price on this one.