what's it worth?

I have a lawn mower with a 5hp briggs & startton motor.
motor works great, in fact I just mowed with it today. the body is rusting out and the cable for the kill switch is broken and rigged up.
I was almost finished mowing today when i had to stop the mower to move some stuff in the yard to finish up and when I went to restart it the pull cord broke again.
I'm getting a new one today but what would a working 5hp motor be worth to someone?

$20 if someone really wants it.

I've tried selling working B&S engines at yard sales, nobody seems to want to pay what they're worth. I barely got $20 out of a Murray push mower this summer. Needed a little work, but the deck was pristine.

Would be good to put on a go-kart.

if you hear of anyone wanting it let me know. $20 would be just fine with me to get it out of the way