Not sure whether to but this hear or GB&C but i found this on a local craigslist: http://losangeles.craigslist.org/wst/msg/2516325438.html

$600 for a Rockerverb 100? there must be a catch! oh but there is. According to the post there's a blown fuse somewhere. I emailed the guy and asked for some details. He said it was two fuses in the back of the amp, accessible without opening the chassis. For $600 this thing is a steal... if it's salvageable but that's where the dilemma is. I'm not sure if the thing is fixable without a complete overhaul. The guy says he hadn't used it in a while and the fuses blew after about an hour, additionally he says the amp still makes noise, its just at like half volume. So my question is does this thing look salvageable or am i better off just looking for something else? I plan on going in this weekend to check it out.
I wouldn't do it.
If it really was a simple fix wouldn't he just keep it?
or do it himself and make a bit more?
more than likely he took it to a repairman who told him he
would have to spend a pretty penny to get it fixed that's why he's selling it
i know it's tempting but i would just hold off.
you are in the right forum

I'd probably buy this in a heartbeat but that is just me.

Honestly, it does sound a bit fishy. Fuses are easy to replace. If he has recorded music and been in a studio he probably knows this already. Now, if the amp keeps blowing fuses after new ones are put in - then yes that is an indicator of a problem.

The problem could simply be that it needs new power tubes. Could be a blown resistor. Could be something more serious.

Great amp though. I personally would take a chance on it.
even if its blow Output transformers, you can most likely replace them, and with the 500 ish you paid itll still prolly be cheaper than a normal new/used one.
If it was me I would buy it. If you don't feel comfortable replacing fuses/tube and aren't willing to sink may another 200 right off the bat then say away from it.