From what you write, your vet doesn't sound very interested in pursuing much in the way of investigations. However, if you mentioned that money is an issue, that may be why? The dislocation could be due to severe arthritis or soft tissue injury to ligaments and tendons that allows the bone to pop out of the socket. Repairing soft tissues can be difficult with no guarantee of success in either animals or humans. Your vet is right about that - the anesthesia would be a certain risk since your dog is a senior. You may need to seek a specialist's opinion at a major teaching university.
Did your vet take x-rays?? She may have arthritis or another bone condition. It might be worth getting a second opinion from another vet.