It may need an oil pump, but it may also need a whole new engine, Cars do not go far with a bad oil pump. Tell them to fix the oil pump first and then have it checked out. I bet there is a lot wrong, but they only mention the oil pump because the light comes on.
you dont want it if the oil pump has failed or is weak , you could replace it and the motor could lock up next week , you do not know what damage has already occured . Oil pumps are cheap 50-200 dollars but you have several hours labor 300-500 dollars