Is there an inexpensive way to fix a blown turbo unit that is leaking oil?
Inexpensive and “blown turbo” don’t go together. So basically the answer is NO.
If the turbine intake side blades have “blown” you will have trash in the engine that may require engine replacement, too.
You purchase a rebuild kit, and rebuild the turbo.
Yep, all comes down to your skill and tools. Can you remove, rebuild, and replace the turbo? Then not much $$. Do you need to pay somebody? Big $$$$
If you do it yourself, expect to be without a running S80 for at least twice as long as if you pay someone to fix it.