I’ve yet to find a ta to get me any discount. Small amount of obc maybe. The last one I attempted to work with wanted to charge me about $700 over the hal website then blamed me for it.
To the op, there used to be a website that did that. Don’t know if it’s around but we can’t mention it. The problem was if you had Mariners pricing it didn’t work for that. Cruise critic had a tool at one point. Don’t know if they still do.