I have not played withe the Stevens 320 specifically, but I have a different flavor of cheap, Chinese made pump 12 ga, and it's not great. Like a Hi-Point, it'll work if it's all you can get, but don't expect a long service life or much in the way of "nice".
I recently bought a Black Aces Tactical semi shotgun on a lark, and it's pretty nice and pretty well made, as well as US made. They have a 18.5" pump gun for $380 at Atlantic Firearms, and I would grab that over any if the Chinese or Turkish entry level guns.
Or troll a gunshow/gunbroker for a used 500/590/870. The days of $200 used Wingmasters are behind us, but some deals are still out there.