I think it's fair to separate the two.
The Patriots are not affordable, but give you a great bang-for-the-buck. The Raiders are very affordable, but give a horrible bang-for-the-buck.
My point is that bang-for-the-buck takes into consideration your team's affordability, but there already was a category called affordability. In essence, what they did was factor affordability into their rankings twice.
Let me give you an example. Lets say the Raider are "rated" like so:
Winning %: 75 out of 100. (assume this our "bang" component)
Affordability: 25 out of 100. (the "buck" part)
Average the 2 you get 50, which is Oakland's "bang" for the "buck" rating. But the Raiders would have been "rated" like this in ESPN's rating system:
Bang for the buck: 50 out of 100.
Affordability: 25 out of 100.
Average the 2 you get 37.5. You have just artificially inflated the Raider's "Bang" and "Buck" stats by figuring in affordability twice.
What they should have done in my opinion is either given a "bang" category that with the affordability category would have given you a bang for the buck rating, or simply had the "bang-for-the-buck" category and not the affordability category. It's not that big of deal since their are other categories as well, but still you are figuring affordability into the equation twice no matter how you slice it. That hurts a team that has a low score on affordability like New England and helps a team that has a high score like Oakland.