All sounds pretty good so far. I had a trawl through eBay the other night, but couldn't find anything about the Quantum amps. In fact, a general Google search of the good ole t'interweb didn't find very much indeed (but did find a thread on here from 2009).
The way I see it, the £300 guide isn't far off the mark given the fact that they were willing to drop £100 off the ticket price on simply asking about the amp. Given the condition I'd say that £300 would be a fair price.
I'm looking for something that will be a good sounding "rock" amp, so I assume that it will meet my requirements. Not sure about the TC / MB points of reference, but I think that I might need to take one of my basses in with me next time I go in there. There wasn't much in the way of Bass stock on show, there was a Mark Bass 300w 1x? combo, a couple of AER's (in their bags, so no idea on model / output), everything else was well under 100w - not ideal for a band situation.
Does anyone know if the quoted 400w for the Quantum is the "full fat" 400w with the internal speakers, or with an external cab?
He was also recommending the Fender Rumble 500, which is on my "would like to try" list, but I certainly wouldn't want to buy before hearing it.