I bough a lightly used trailed and it had this TB Controller on it. I don't need it, as my truck has it built in.
New versions of this seem to be around $800 on Amazon.ca
The only difference that I can see is that mine doesn't have Bluetooth.
The trailer that this unit is from was used for about a season and that's it. When I had a trailer shop inspect the trailer, they also checked this controller and everything works just fine. $300 for a quick sale.