Google your fridge model along with "amish" and you'll get some hits on good, replacement cooling units. I don't know if there are core charges on rebuilt ones. I bought mine from eBay. The seller was someone that liquidated the inventory of failed businesses (in this case an RV repair shop). He knew nothing about the cooling unit but I did so I got it cheap.
I see no reason to involve a dealer who is just going to mark up the cost of the cooling unit. If you can't or don't want to install it yourself you can get the cooling unit shipped to you cheaper than the dealer and find someone to install it. It's a tedious job but not terribly difficult. There are lots of videos out there. I did mine in a few hours and popped it back in. It's worked great ever since (going on 5 years now).
EDIT: I googled it for you :)
https://rvcoolingunit.com/RM2652-Dometic-Cooling-Unit-606a-626a-P231900.aspx