Does Sanji have the highest first bounty in the series that we currently know of? Let's compare among the Straw Hats:
First bounty:
Luffy: 30 million
Zoro: 60 million
Sanji: 77 million
Jinbe: 76 million (although we can't be certain if that was his first bounty ever)
Second bounty:
Luffy: 100 million
Zoro: 120 million
Sanji: 177 million
Third bounty:
Luffy: 300 million
Zoro: 320 million
Sanji: 330 million
Fourth bounty:
Luffy: 1 billion
Zoro: 1.111 billion
Sanji: 1.032 billion
(Zoro caught up)
Fifth bounty:
Luffy: 1.5 billion
Zoro: ??? (Prediction: 2 billion)
Sanji: ??? (Prediction: 1.9 billion)
Sixth bounty:
Luffy: 3 billion
Zoro: ??? (Prediction: 3 billion, after defeating Mihawk)
Sanji: ??? (Prediction: 2.5 billion)
I predict Luffy's seventh bounty to be at around 4 billion while his eighth and final bounty will surpass even Roger's.