I think that particular kit IS overpriced for the reason stated above - it has BnB lugs on it. Ive owned a english rogers snare with those on, they cracked and made it almost impossible to tune. If you are lucky enough to find one of the last UK kits, itll have the better beavertail lugs fitted.
If I was to make the guy an offer how much would you advise? I'm happy to restore the kit and I'm not too bothered about originality lug wise etc as long as the kit had a nice vintage sound. I'm sure it would be better for the money than a modern Chinese made kit??