Depends a lot I guess where you live and what Country you are in but here the LPG regulator (auto change over type) cost around $250 for the part complete with the two flexible hoses ( pigtails ). You would have to take into account as well as the part price the travel and labour content from the tradesman undertaking the work also. How much were you charged anyways??
Selgas Services Ltd Craftsman Gasfitters, Plumbers, Electrical Service Technicians