The Maverick is basically a Mossberg 500 with a different safety. The 500 has the safety on the tang while the Maverick M88 has the safety on the trigger guard. Most other parts will interchange between the 2. The thing with the M88 is that you cant add magazine extensions. Its just how its made, you need to change the entire mag assembly.
It will go bang every time you pull the trigger. Its a cheap, no frills reliable and dependable gun. With pump shotguns, failure is mostly due to operator error. Short stroking, forgeting to release the safety, wrong ammo, etc.. Mechanical malfunctions are rare on pumps.
The reason its cheaper than the the 500 is its positioned as an entry level item. Its also assembled in Texas using Mexico made parts.