Hooking up satellite

If you are planning to use 2 DVR's plus a 3 box you are going to have to use an open face antenna just like the one on your house. You can mount this on a tripod and take the time to learn how to point it. I would recommend that you get a SWM SL3 antenna as you would then only need one coax cable running to each receiver. Just be aware that none of the dome (portable or roof mounted) will have enough connections available.
Winegard also has a roof mounted fully automatic antenna that would allow you to connect all of your receivers.
$200 actually sounds like a bargain to me considering the amount of wiring that will need to be run, but I doubt they would actually do it once they found out what you actually wanted to accomplish.

What receiver model?
Once you have figured that out, look online for sany of several online retailers that offer a complete package, Dish and tripod and but one. Then, depending on how you connect, SWM or 4 wire you will need to go buy some coax cable. Find a suitable place inside where you could run the wires without having to drill more holes in the side of the RV. Since I run a 4 wire setup from my ground antenna, I bought two thru adapters that are mounted inside a compartment. Then I ran wire to the two places I wanted inputs and installed wall plates for the cable. If you go with SWM all it requires is one coax from the dish to the SWM power supply and splitter, Then another wire from the splitter to the Second TV location.

Do it just like it is done at home. If it worked there, it will work in the RV the same way.

If you have a SWM setup you only need one wire in, and it can't go thru any splitters.

If you don't know what I just said, you can google 'dtv satellite diagram' or go to directv.com and find installation instructions, or just wait here.