Though I couldn't imagine how safe having 5 billion dollars would be considering it is just asking for Rockstar to ban and/or rest your account. I wouldn't recommend getting that much.
roughly 350 million would buy you everything in the game (your choice of vehicles, all Pegasus/Warstock/Elitas/Docktease, vehicles, all 5 properties, yacht, offices, warehouses, all clothes and accessories)allowing for plenty of mistakes, resprays, etc...
600 million to play the game comfortably is a good boost if starting out with nothing, although I give my accounts 2 billion. Since it's a recovery...I don't know if they go ahead and purchase Pegasus/Warstock/Elitas/Docktease vehicles for you. I always purchase with modded cash before transfer, and never use the "FREE" option. 5 billion, and you'll never get any car sales stats...ever!! If you have everything purchased or not, that much cash will never be spent....not even close.
Last winter there was a PS4 account duplication glitch going around and I got over 28 Bil.
Over all this time of buying stuff I like and previewing all apartment styles and stuff I am now at.....well 28 bil. Lol.
5 bil is more than enough. I just happened to get 28 bil in the process of acquiring cash. I think 100$ mil is actually all you need in this game to buy everything you like.
Question has been answered, I am going to move this thread to the archive, if you have any more questions please feel free to post another thread so the community can help you out!