Pump shotguns r a gun I would not be afraid to buy used. They can be had for less than $200 and it is very hard to wear out a pump.
I bought an old Mossberg 500 with wood stock and poly-choke a few years back for $130... it functioned flawlessly. Since I had made my modern 500 into a HD shotty, I had a spare barrel with replaceable chokes. Last year I handed it down to one of my grandsons and it is still going strong. If buying now and had a choice between single shot hammer style and pump, I'd definitely spend the extra dough for the pump.