My personal view is that until you have tried all the cheap ones, you shouldn't.
There is nothing particularly different between a $300 O/U and a $3000 O/U other than things that don't make it shoot any better.
Expensive shotguns just have fancier stock and finer engraving and prettier colours, and if you really want to pay than they can also customize and build a gun for your length of pull and balance it for you.
They don't shoot any straighter and they are not any more reliable in terms of click/bang ratios.
But fancy shotguns are easy on the eyes.
(Not my shotgun)