We have Dish at home and so have Dish in the RV. We get the same 200 or so channels in both. First several years we just added the RV to the home account for an extra $7 per month. Fine at first, but my daughter moved in with us. When traveling out of our home area and I changed the service address to get local network channels from our nearest local city at the time my daughter could not get our home locals at home. Later I changed the RV to a separate pay as you go account so it doesn't affect our home account when I change the service address and I pay only for the months we use it.
Program packages are available for under $50/mo (I think) and up depending on how many channels you want. Receivers and manual antennas are not overly expensive. Check dishformyrv.com for pricing. Automatic antennas cost more.