Are you a full timer, long timer, or sometimer? If you only intend to use it on occasional trips, the Dishformyrv pay as you go plan would be good. You only have to pay for the months you use it. And don't pay for the other months. Basic plan I believe is about $50/mo, and up depending on how many channels you want to pay for.
If you have Dish at home, just add the RV to the home account for $7/mo. You would need to buy an additional receiver for the RV. Some people take a receiver ftom home when they travel, but l prefer to have one I can just leave in the RV.
We have had Dish both at home and in the RV for many years and very happy with it. I used a tripod mounted antenna for a couple years, but never got very good at aiming it. Bought a Tailgater and let it find the sats automatically. With Dish, when traveling outside your home area you can call (or on line chat), tell them your current location, tell them you want to change your service address (not billing address), and in a few minutes you will have major network stations from the nearest local city.