cargo heater rv3000 replacement

PROBABLY SHOULD HAVE GIVEN SOME MORE BACK GROUND INFO ON COACH, I DO NOT HAVE THE COLD WEATHER PACKAGE THAT INCLUDED SOME OF THE EXTRA INSULATION AND THE HEATING OPTION ON THE BLACK/GRAY TANKS (I CALLED MONACO AND ASKED) I AM SECOND OWNER OF THIS RV AND NOTICED THAT IN EXTREMEMLY COLD WEATHER THE HEATER IN THE BAY WOULD NOT COME ON, SO I HIRED A RV REPAIRMAN (I LIVE IN A RURAL COMMUNITY) AND HE SAID THAT THE CARGO HEAT RV3000 WAS BROKEN AND YOU COULD NOT REPAIR, JUST REPLACE, WHEN MONACO SAID ALMOST $400 WITH TAX AND SHIPPING, I STARTED LOOKING FOR OTHER OPTIONS, AS I HAVE READ OTHER PEOPLE HAVE ONLINE, AND NOBODY HAS MENTIONED THE BACK SEAT HEATER THAT IS THE EXACT SAME SIZE AND APPEARS TO BE THE SAME THING, SO I JUST WANTED TO SEE IF ANYONE ELSE HAS INSTALLED ONE OF THESE IN PLACE OF A BROKEN CARGO HEAT AND DO THEY KNOW HOW THEY HAVE PERFORMED AND IS THERE ANY CONCERNS I SHOULD BE AWARE OF. THANKS