Need lower pan of part 31 and need part 32/gasket sealant for the pan. It can be fixed for under $200.
It can be done cheaper if you want to use a Time-Sert. This is an approved VW/Audi fix. Catch is its typically an Aluminum pan fix so it would be a lot hard to do it this way with a steel pan.
Edit: Added more information for addition fix for you.