Top 10 lists from a site called collegespun, which I don't know much about. But it's based on current stubhub prices, so not a difficult analysis. Two lists, one for the entire county and one for the B1G.
Michigan-Notre Dame is the most expensive game anywhere next year, by a long shot: at $428 it's more than $100 above the next most expensive game (the Iron Bowl), while The Game comes in #4 at $307.
For B1G games, Michigan and Ohio State dominate the list. Highlights are #9 at Sparty for $153, #6 hosting PSU for $159, and the aforementioned ND and Ohio games, which are #2 and #1 on the B1G list, respectively.