Well if you can see swelling then it is unlikely that the pelvis is the problem.
Usually with a dislocation there will not be a lot of swelling but when the calf stands the hips will be a different height. This can be hard to tell if they are trying to stand on three legs.
Really serious fracture like femur (thigh) fracture are uncommon unless the cow stepped on him or he was injured during an assisted birth.
A veterinarian should be able to get a good idea of where the fracture is upon exam. If it is the pelvis that is fractured some of these animals will heal enough over time (with restricted activity) to have a comfortable existence. Since he will not be around more than a few years and he will not deal with too much arthritis.
A fracture of the femur is harder to cast. Proper fixation may require surgery. A fracture of the lower leg (which you mentioned is unlikely) this type can be casted if the bone hasn't moved too much or gone through the skin.
Best case would be a farm call, exam, sedation and cast for a fracture or reduction of a dislocation. $200
Worst case is a farm call, exam and euthanasia (because of a bad fracture that you can't fix.) $75-$100
Also bad would be a fracture that can be fixed but will require surgery. This will cost $400 and up. Depending upon what prices run in your area.
If I can answer anything please let me know.