What do you mean by "saver bf"? What fare bucket is that? BTW, during August you can probably find Z fares for about $2000 to $2500 round trip in BF. If you can find a good z fare, it is not worth it to upgrade with miles.
Saver Business is I, or IN for Plats/1Ks.
He wasn't upgrading with miles, was trying to use a GPU.