Based on ebay prices you should be able to get something around £120 for each amp. Personally I think this could sway to £140 for the power amp and £100 for the integrated based on their availability. I used to have this pairing and sold them both for £250 some years ago.
igglebert:Based on ebay finished auction prices they're going for what I sold mine for over five years ago.
.... Which sadly isn't very much. Arcam stuff is unusual in being fairly popular, resulting in usually 4 or 5 pages of stuff on eBay, but also polarises opinion. This has an affect on supply & demand and keeps used prices relatively low.
Great if you're buying, not so good if you're selling.