I'd propose the sliding scale of prestige, with the top cap on non BCS schools just below the overall max, and the bottom cap on current elites being quite high. A bottom cap would be rewquired because frankly you need to account for all levels of schools.
For example, on a scale of 1-1000, D3 schools might be 1-300, D2 schools 250-550, D1AA 500-800, D1A non-BCS 750-950, BCS 850-1000, Elites 925-1000.