In short, not much. In brand new, unfired condition you
might get $120 for it on a good day in a private sale.
In good, used condition, maybe $80.
It's not a high dollar gun by any means, and it's not at
all well regarded. Some of them can be good shooters,
and the fact that it *IS* a real gun, capable of firing live
ammunition gives it at least some value.
Sorry if that's not what you were hoping to hear, but
there it is. Jennings/Byrco is solid bottom shelf stuff.