Is yours like the one on ebay? Fancy flange, nice resonator, short neck? My quess would be about $400. Although I doubt the ebay one is going to go for much more than $300-$350. The other problem is you need to find someone willing to pay that much. Tenor banjos are not very popular these days, the only people who play them are Irish music, (short scale), and Dixieland (long scale). And for someone who is willing to look around, a decent banjo can be had for significantly less than what I've quoted