Imo Vegapunk easily easily will get a 4 billion beli bounty let's break it down
1- he has command over pacifista and the seraphim only the gorosei is above which is why Saturn is on egghead in the first place
2- his knowledge is invaluable and he can easily create something to over power the seraphim and even reprogram them to ignore Gorosei orders
3- studying ancient history
4- can produce the mother flame something that wiped an entire nation off the map
If Vegapunk could fight I'd argue for 5 Bill but I'd say 4 bill is fair given how dangerous his intelligence makes him especially if he permanently allied with luffy or joins up with dragon
1- he has command over pacifista and the seraphim only the gorosei is above which is why Saturn is on egghead in the first place
2- his knowledge is invaluable and he can easily create something to over power the seraphim and even reprogram them to ignore Gorosei orders
3- studying ancient history
4- can produce the mother flame something that wiped an entire nation off the map
If Vegapunk could fight I'd argue for 5 Bill but I'd say 4 bill is fair given how dangerous his intelligence makes him especially if he permanently allied with luffy or joins up with dragon