1996 Toyota Corolla Overall cost to fix all at once

Engine Performance problem
1996 Toyota Corolla 4 cyl Automatic 80+ miles

got car in 1998 used, never changed timing belt, know it's overdue. Have oil leak, seems to be high according to 2 mechanics, as long as I put 2 qts in every other week car runs with little leak, more than that leaks all over the engine, etc, a mess! To do both at one time makes sense, any idea of cost? Thinking $450 for timing belt, but leak I am told is so iffy no one will quote even ballpark.