Craignanson

Wondering if anyone can help me. My son has had a oset 20r for a couple of years now which we got second hand, 6 months ago he has blown the motor ( Burning type smell and smoke coming from it) We have been unsure about getting it fixed because of the cost of the new motor. Would this be sellable without been repaired and anyone got any idea of price that we could sell for . It worked fine before this happened and my son has had a growth spurt so no longer any good. It also has the boost battery. Cheers