If I may paraphrase the question, what is the lowest cash bonus my boss would have to pay me in order to get me to fly in BF instead of GF? In my case, that would be close to zero.
Or if I may paraphrase the question again, if my boss gave me a $100k bonus, how much of that money would I spend on upgrades to GF? Again, in my case, that would be close to zero.