I bought a 410 Moss 500 for $200.00 a decade ago. my advise is to go to Action site & see what they are bringing, before dealing with a pawn shop.
http://www.gunbroker.com/
http://www.gunsamerica.com/
A shotgun is a much safer buy,when buying used. compared to rifles.
Hear is a nice 870 package deal for 300.00
http://www.thehighroad.org/showthread.php?t=601960