In the realm of pumps. . .
Remington, Mossberg and Winchester all make good, reliable guns that shouldn't be much over $300 NIB. If you have a friend with an FFL, you can get a Win 1300 for about $210-$230, depending on where you buy.
Also, AIM surplus has sales (from time to time) of used police 870's. They usually run $160, when you can find them.
Ben