They're worth what the market dictates, probably around £325-350 at the moment, given the general financial situation.
Last month there was a nice Rapid up for only £600 with little or no interest, just market conditions.
I had a Logun rifle mk1 & loved it, especially the tube magazine, but obviously it is limiting unless it has the spare shuttles for different pellets,
plus with a rifle of that age there needs to be good spares support.