I have a Brolin pump, that took some tweaking to get it reliable. The magazine spring was crap, and it was failing to eject rounds from the magazine into the chamber until I took it apart and reassembled it. Also, the mag spring was weak and needed to be replaced. The wood on mine is also pretty soft and very prone to knicks. As a beater, it's acceptable after a little tweaking, but I don't know if that's what you're after.
For a cheap semi, the people on the forums at www.shotgunworld.com have been raving about the Baikal MP153 that's being imported by EAA. CDNN has them listed in their latest catalog.