If it was a Benelli supe
r nova, then I would probably say go with that one. The super novas are very fine shot guns. The standard nova, not so much. But, even if it was a super nova, I would be hesitant... while a better gun then a mossberg 500, there are not many options for customization and the few that there are, it is VERY expensive... barrels included.
Both Benelli nova or Super-Nova models are more expensive then a standard Mossberg 500. So, if it is purely looking at it from a monetary point of view, trade wise, then the Benelli's are the "best" trade.
The standard Nova is about on par with a Mosberg 500 quality wise (debatable, but my opinion). If the trade is for a personal use of the gun, then I would lean towards the Mossberg 500 due to the total cost of ownership for customization over the long run.
I own a Mossberg 500 and I am totally happy with it