User blog comment:Mythical zoan fruit enthusiast/The thing about Buggy's crew..../@comment-176.25.185.43-20130420064048

There were around 240 Impel Down prisoners that escaped according to the wiki page. If you take away the big shots like Luffy, Crocodile, Jinbe ect it would come to around 230. And if we take away the revolutionaries and  it became around 130. Lets say that atleast between 50-100 of those prisoners joined Buggy and all of them had bounties of 15,000,000.

That would mean his total crew bounty would be a minimum of 750,000,000. And we can speculate that some level 3,4 and possibly 5 prisoners may have been fooled by his past and joined him. And that would mean his crews bounties could be between 15,000,000 and around 60,000,000 or more.