If bounties represent the danger that person is to the WG, it makes sense that Shanks would have the highest. He has something up his sleeve that makes even the Gorosei do what he wants.
I can live with whatever bounty Oda decides to give him. I just want him to look cool on his poster.
3.89 B
3=mi
8=ha
9=ku
(doesn't really work bc his Japanese name is Mihouku, not Mihaku, but I still have hope)
Even better, it could be 4.6B
4=yo
6=ru
But in the end, it doesn't really matter. I expect that other people, including Shanks, will have higher bounties. It is what it is. Be like Mihawk and don't overreact.