I don't think anyone said they need to play 8 or 7 to make budget. It's just their stated intent, but certainly there is a financial incentive, and a fan incentive, to play at home as much as practical. You're probably in the minority of fans who are okay with just six home games. I'd offer to pay Vandy off and get a ninth home game when they cycle through.
There is a direct correlation between stadium size and number of home games. Of the schools with the largest stadiums, Penn State plays eight this year, Michigan eight, Ohio State seven, Tennessee eight and Texas seven. D-1 schools with small stadiums (under 31,000) like Central/Western/Eastern Michigan, New Mexico State, Louisiana Monroe, Louisiana Tech, Arkansas State and Troy play five home games. North Texas, San Jose State, Kent State and No. Ill. play six. Boise State plays seven home games, but they play 13 this year (I guess because of the Hawaii game).