I don't see him spending half of that figure on the club,Ashley at Newcastle or Short at Sunderland are worth an estimated 2-3 billion each and spent no where half of their wealth on their clubs,same can be said with Abramovich at Chelsea or Lewis at Spurs.
Billionaire stay billionaires for a reason because they play it safe with their money and only invest when there is a return or profit.
Plus with FFP still around owners cannot just spend nilly willy of old,Chelsea got lucky as they was no FFP and spent around 600-700 million on player recruitement before FFP came in,since then Abramovich modus operandi is the club only spends what it makes as he wants the club to be self sufficient by improving the turnover,the days of him splashing his own cash have been over for a few seasons now.City have gotten past FFP by nefarious means of creating a different company that funnels a sizeable chunk of the percentage of the players wages so the wages in the actual turnoverlook lower for FFP,also they have owner linked Commercial deals with Etihad Aabar Arabtec Etisalat and AbuDhabiTourism that gives them a commercial revenues of £173 million pounds which is ranked 2nd in world football hahaha,they also rig the matchday revenue by claiming to have a full stadium when every game has lots of empty seats.
I think the first thing Moshiri will want to do is improve the playing side but it will no where near what Abramovich and City have done,also he will want to improve the most important thing in Turnover these days which is commercial revenues and then matchday revenue with a stadium move to maximise the potential of the club.
