Do you think I should spend $2600 and add exhaust brake?

I bought a 04.5 Ram CTD one owner a year and a half ago. Previous owner had put a Pac Brake on it, with auxiliary air compressor fitting, obviously was very professionally installed. I feel fortunate that it had the Pac Brake on it. It's pretty amazing towing down grades. As some said, generally don't even need to use the service brakes. I'm sure the resale will be a bit higher whenever I decide to sell it due to the exhaust brake.

I'd say get one if you can afford it, but up to you whether to spend the $ or not.