Trailer hitches are not generally included for free when purchasing an RV. The hitch itself and its installation can be expensive, depending on the type of hitch and vehicle involved, though some dealers might offer discounts if buying the hitch from them along with the RV.
While simple ball hitches can cost as little as $8 as of 2015, hitches adequate for towing very large RVs can cost as much as $2,000 for some fifth-wheel hitch models. Hitches that need to be customized for a particular vehicle are usually more expensive. Installing a large hitch may require welding, drilling and cutting metal, adding between $200 and $500 to the cost of the hitch if done by a professional installer.