I agree that $350 is a good deal.
$300 is a VERY good deal
$250 is a GREAT deal and anything less an Outstanding deal.

Like wise you could replace the prices with the words, Original grips, Like new and NIB.
Incidentally I just picked up a 5 screw with wrong era (Smith target) grips or $375 with some muzzle wear.
Also paid $400 for a LNIB 15-1 last year.