I've owned Brownings, Beretta's, Franchis, Remington CZ's, Lanbers and ATIs in O/U's in recent years. I still keep a favorite in most of those brands. ( The nes I shoot well.)
Yes, Browning and Beretta's are King (in price, lifetime retention of value and build quality). Personally, I don't see the reasoning in spending north of $1000 on your first O/U. It won't make you a better shot. IMHO, the higher end Lanbers and CZ's will get you 85-90% of that quality at 40-60% of the cost. These companies make some very nicely appointed O/U in the $700-$900 range. IF your budget is tighter, the ATIs and Remington imports will get you thousands of rounds of use for under $500. BTW, Mossbergs are everywhere but have a bad rep for quality (that I have witnessed.)
That said, don't get caught up in the snobbery that often comes with shotgun sports. The most important thing about a shotgun is FIT since there is no rear sight to line up on. Your either looking naturally down the barrel or you are not when the gun comes up. THAT has nothing to do with price.
"If it doesn't fit, you won't hit!"
Bottom line: Do some online research on fit and features before laying out cash on a gun that may not work for you.
As for qaulity, shotgunsdotcom has some pretty honest user reviews.