How much does a typical vacuum leak repair cost?

Depends on leak location and what would have to be done for access and what is leaking. Or just do like some people on here do, just start replacing anything that vacuum travels thru till you still cannot fix and then hit us back with your hair all pulled out. Pinpoint the source then ask the question. There is no such thing as a typical vacuum leak but suspect you mean you have a leak in your emission system and likely the tank vent system.