I think the price is about right given its a bit of a niche machine. .
Ownership criteria being........
1) Likes old bikes....
2) and has lots of spare garage space .....
3) ......and in a relationship or has some very "close" friends who are big/small enough to fit the frame size and trust you enough
4) .....and who are also into cycling
5) on very old bikes
Price is probably spot on. I would stick out for the 400 though. If as you described and not rusted up its got to be worth that.The frame alone would set you back more than that nowadays. There has been one or two over time on e bay and I think they were round about the 400 mark