As long as Boise is spending money at a rate like a B5 school they will do okay. They are willing to accept some marginal guys and they can sell winning and a very supportive environment.
Add that to playing a MWC schedule along with a couple of Sun Belt type schools a year in the OOC and they are not going to drop far in the win totals. Worst should be 8-9 wins a season.
The hitch in this entire scenario is do they continue to spend the $$$$$. The plan was to spend the money, win a bunch of games, get the rankings and the publicity and force themselves into a BCS level conference, preferably the PAC or the B12 but even something like the Big East would have been acceptable. At that point the media money would have taken the place of the millions that the school and the community was putting into supporting the program at that level.
The got the wins, the rankings, and for a while were the topic of conversation (will Boise get a shot at the NC?) but the major conference bid never came through. They thought they had the Big East which would have been a bad combination for travel but would have brought them a much bigger chunk of money than the WAC/MWC but that fell through.
Now the school is facing some budget issues, the Boise economy has taken some hits, and that subsidy to the BSU football team is looking like a bunch of money. It is a real question how long it continues and without that subsidy Boise becomes another typical MWC team.