I had a Benary Banjo once. It played fine and sounded good. Probably Epiphone or GoldStar of the day. Old rule of thumb was the more hooks and brackets the more valuable it was.

If the neck is straight, all the hooks are there, the tuners are up to date, and you can get a new head on it and it sounds good, its worth what it takes to own it.

If its just for a banjo to play, anything over $400.00 and you can get a new one. Or at least more modern if thats an issue.

I wouldn't pay more than $250.00 for one ( Benary) right now unless it was like new.

Don