BNIB then £350. Mint then £300. One ding on stock -£30.
A nice but used then £200 and well used a good bit less; here "overpriced" is common.
Prices did go up but possible fallen again. Its the high price for new rifles that secure a good price for good rifles. The premium for mint has increased, non mint less so, which means the disparity is widening marketably.
Quality of period extras can add quite a bit if the quality matches. Add a Hawk scope adds nothing.