Take-Two Interactive may have allocated a max budget of $2 billion for Grand Theft Auto 6.
According to newly published DMs with the infamous GTA 6 hacker, the upcoming Grand Theft Auto game could be the most expensive title in the series. The leaker, colloquially known as "teapotuberhacker," was reportedly in discussions with other hackers regarding the stolen Rockstar Games data. Throughout the DMs, the hacker claims that Rockstar has spent $2.5 billion on GTA 6 so far--a number which has since been amended.
This is an incredibly high budget for any entertainment property, and would make Grand Theft Auto 6 the most expensive video game ever made. The information is incredibly shaky, however, and shouldn't be taken as 100% fact.
If genuine, this number would reflect the entire budget for the game including: years of development costs (GTA 6 has reportedly been in early planning phases since 2014); marketing and advertising deals, which can be expensive; full publishing and distribution costs of physical and digital media, including overseas shipments; any post-launch content including expansions and story DLC; and the lucrative online component for GTA 6.
The last spending point could be pretty expensive if Rockstar Games is aiming to use GTA Online to bridge both GTA 5 and GTA 6, similar to how Warzone connects multiple mainline Call of Duty games.
Again, we have absolutely no idea how much money Take-Two Interactive or Rockstar Games have ear-marked for GTA 6, but bear in mind the game dind't enter principal development until 2018.