I have always wanted a O/U in 12 ga. I have a tight budget and could only spend about $500 max. What is out there that would be a good low budget O/U?

Id save more money. Youll be happyer with a nice gun, Look at used ones . I picked up a Older Bereta 686 special for $750. The old "specials" are nicer than the newer silver pigeons.

You can get a Russian Baikal (also imported as Remington Spartan) or a Brazilian-made OU for less than $500, but I wouldn't recommend either. Watch for some old boy that's down on his luck and you might be able to pick up a nice used Citori, Ruger Red Label, or Beretta for $600-$800. The older Berettas imported by Galef (Silver & Golden Snipe) and the BL-series are excellent guns, but usually sell cheaper than the current 6-series.

I would take the advice and look for a used Browning or Beretta. The Brownings are made by Miroku for Browning (I own a B325)and mine has many thousands of rounds through it and is as good as the day I bought it. I wouldn't go cheap on a gun that might be used a lot.