Where the heck did you pull that number from? A billion just to relocate a team?
But the point of the debt load argument is fairly simple. Do you make more money (which makes it faster, easier, and indeed even possible to pay off your debt) in a big market town with higher ticket prices along with more and bigger companies to pay big bucks for luxury boxes, or a blue collar town with very little big business but a very rabid and loyal, though largely poor (according to the census), fan base? The answer is obvious.
What Bills fans need is a White Knight who can afford to sacrifice profitability to keep the Bills in Buffalo. And even if such a Knight existed, the other NFL owners have a big say in the matter so even that isn't a guarantee.
Remember too, that when Golisano was the White Knight for the Sabres, I believe he paid less than 100 million for the team (92 if google is correct ). That's a far cry from almost 900 million the Bills are estimated to be sold for.