Pro Mariner offers an upgrade policy. If you have a roached unit, you can call them and they will give you a special deal on a new one direct.
I also happen to have a 3-bank pro-mariner 30A unit in perfect condition (upgraded to a 40A Newmar on the cruiser). If has the black case (not the stainless steel case). I'll be willing to part with it for $200 plus shipping.