Brian,
Yes, that's probably a self installation estimate with better quality components. Plus, I bought our stuff about 10 years ago, so there's probably some inflation. There are a lot of options as to tow bars and brake systems. There are some cheap tow bars out there, but they're more finicky to hookup and unhookup. I wanted "easy" and rated over the towed weight, so I went with our Aluminator. :) But you can also pick up tow bars and brake systems used to save some $$$. Installation isn't rocket science. If you have experience doing your own auto maintenance, it's not too bad of a job. The tow plate and brake system took the better part of a weekend, but it was during hot summer weather and I didn't kill myself working on it.
We tow our Odyssey with our W-22 Workhorse 8.1L gasser with Allison transmission motorhome. Our Odyssey weighs in around 4,400 lbs. without anyone inside. Fully loaded (for a long trip/vacation) our rig weighs in near 21,500 lbs.. So towing the Odyssey we flirt with the 26,000 lb. GVWR on the chassis. We do stay within weight limits and while I can tell it's back there, the rig still does OK pulling around nearly 26,000 lbs.
~Rick