The Maverick might be ok, but whatever shotgun you choose, make sure you get one that has a long barrel with the option of using screw-in chokes. Why? So that you have the equipment to hunt birds, and play clay pigeon sports (Trap, Skeet, Sporting Clays and so on). Why? Because you never know when you might have to put food on the table, and shooting Skeet/Trap is FUN! The removable chokes allow you to do the tuning of the pattern you'll want to do (ask an experienced shotgun hunter/sportsman for which choke is ideal).
Usually shotgun barrels are able to be taken off/swapped in less than 20 seconds or so, it's usually nothing more than cocking the action to the rear, unscrewing a nut and pulling the barrel out of the action. Sometimes a shotgun might come with two or more barrels, for more utility. One like the hunting/sporting barrel mentioned above, and a shorter "cylinder bore" barrel that's ideal for using slugs and buckshot.
I bought a second barrel for my Remington 1100 (basically a Remington 870 but semi-automatic) off the EE "parts and bits" for $150.
The 870 is outstanding value, and can be had pretty cheap. Get one with the hunting barrel I describe, then go to CanadaAmmo dot com, and order one of their 12.5" barrels for slugs and buck, s**ts and giggles! That would give you the most versatile/cheapest shotgun with long-lasting value.
Remington 870 = the SKS of shotguns!