For a roof/wall mount, Dish is supplying braces that should help the dish deal with wind load. They work like a tripod with the mast.
We're only installing pole mounts if there's no line of sight anywhere else due to the cost of the pole and concrete. (some types use a 2" 8 foot pole which is hard to find with the proper load specs, so it can be expensive if Dish's supply runs dry) The other type uses a standard large fence pole, and can be easier to find.
For that reason, some subcontractors may charge for the pole mount if you choose to go that route, and bypass the roof/wall mount with braces. If the pole is the only line of sight, they shouldn't charge you because Dish is obliged to supply locals at zero cost to customer.
Bottom line, they should only charge you if you decline a free mounting option. My personal opinion is $40 bucks to a contractor to pole mount the dish is cheaper and less headache than repairing your roof should a major storm come through.
