To be fair Shaun a lot depends on the condition.
If you did the paintwork a few years ago and the bike hasn't moved since it will need recomissioning, possibly a lot of the brightwork will need rechroming, battery, tyres etc.
Having said that around 2 - 2 1/2k wouldn't be an unfair price if it needs that level of work. The racing engine, again, does it run, has it been rebuilt, what state of tune? The flat-slide Amals are interesting if somewhat archaic, but nice, simple carbs to work with.
I'm with Miffa, if you can get it for anything under 3 grand for the lot and you are quids in!