Why would a dealer react the way that you say...
A few thoughts come to mind, they are so busy that they couldn't care about their business and particularly new customers like you who they have never dealt with before. The dealer is so flush with cash, that a $13K sale is peanuts to them, as their typical buyer is spending millions of dollars every year...or maybe they are doing the business as a hobby, and the same thing applies with their customer base. Lastly, you are asking for a trade in, which means they have to write an ad and try and sell your traded in gear, that takes some effort.
I think these guys are doing you a favor with their responses ( or lack thereof)...they are telling you to take your business elsewhere and give it to a much more deserving person. They are also demonstrating to you what their after sale service would like IF you made the mistake of buying from them in the first place.