There are three types of Encore 50 cals. and the prices are different for all three. Some go for upwards of $900 new!! I had one and didn't like it! I wouldn't pay that any time, ever. But don't take my experiences to heart. Many people love them and swear by them. If it is a Pro Hunter the SMRP is $650. Check out:
https://www.tcarms.com/firearms/muzz.../pro-hunter-fx
How much is your gun worth that he wants to trade for?
Falcon:
I didn't know there where muzzy only Encores??? Good to know if so, thanks