Is it rusted through on the side or is it paint/tar/oil splatter I see ?
What do the teeth/nubs look like inside ?
If teeth are good and bearings are good and it's not rusted through - $100-$150
If it's rusted through I wouldn't give more than scrap price, though you could probably get $50 for "yard art".
That's up here in PA, I don't know about down your way.