This is a list of Luffy's bounties if all his feats had been taken into account:
East Blue: Luffy defeated Alvida, Morgan, Buggy, Kuro, Krieg and Arlong. However, the Marines only knew about Morgan, Buggy, Krieg and Arlong. I'm also considering the fact that he has an Akuma no Mi on the weakest sea, which was a great advantage there.
Buggy + Krieg + Arlong = 52M. I'll give him 3M for defeating Morgan and 5M for being a Paramecia. So Luffy's first bounty should've been 60 Million.
Arabasta: Even though Smoker took the credits for the Arabasta Incident, Luffy was also responsible for Wapol's defeat, who was also a WG affiliated kingdom as he himself stated. Considering a 60M bounty, I'd give him a 90M increase for his brotherhood (or at least friendship) with Ace being revealed to the Marines while also defeating a Shichibukai. Luffy's 2nd bounty should've been 150 Million.
Enies Lobby: Luffy has now a 150M bounty. I'd give him 100M for assaulting Enies Lobby, 100M for declaring war against the World Government and 50M for escaping from a Buster Call targeted at him, destroying Enies Lobby in the process. Luffy's bounty should've been 400 Million.
Marineford: I'll consider all his feats from Thriller Bark to Marineford. Also, I'm considering that this bounty would be issued after his return, as it would be pointless to issue such a high bounty for a crewless pirate whose whereabouts nobody knows.
Defeating Moria: +50M.
Hitting Charlos: +300M.
Impel Down breakout: +50M.
Summit War: +50M.
Being Dragon's son: +50M.
Being a Haki user: +100M.
Luffy's bounty (after returning to Sabaody) should've been 1 Billion.
Dressrosa: Having a 1B bounty, Luffy would enter the New World recognized as a big threat. I'd give him the following increase:
Punk Hazard Events: +50M.
Allying with Law: +50M.
Dressrosa Events: +100M.
Luffy's 5th bounty should've been 1.2 Billion.
Whole Cake Island: I'll assume that the Marines only know about both Cracker's and Katakuri's defeats. So, in this case:
Defeating Cracker: +300M.
Defeating Katakuri: +500M.
I won't give him any increase for challenging Big Mom cause that's not big deal for a 1.2B criminal. So, Luffy's 6th bounty should've been 2 Billion.
Wano Country: I won't equalize his bounty to Law's and Kid's. Luffy is clearly the strongest of them.
Defeating Kaido: +1B.
Awakening the Nika Fruit: +500M.
Joining the Yonko: +500M.
Luffy's 7th bounty should've been 4 Billion.
Elbaph: He doesn't have big feats there yet, but I'll assume that he'll defeat Loki and the God's Knights (with Shamrock), forcing them to retreat.
Egghead Incident: +250M.
Elbaph Events: +250M.
Luffy's next bounty should be 4.5 Billion.
Thoughts?