Body work -- that is, GOOD body work -- is not cheap. And forget about Macco altogether if you're trying to get a decent job done.
The general process on visible areas is this: grind or sand to good metal, prime and treat, then paint. Non-visible areas can get POR-15 treatment, that's about all they'll need for surface stuff. Body mud may be necessary for visible stuff; welding may be necessary for structural integrity issues and serious non-visible problems.
best, whit