Every 100 million raised by player sales can fund 500 million of purchases if the players sign five-year contracts.
The problem with this theory is that it isn't perpetual and it ignores the debt that continues to grow. See below.
Year 1. Sell 100, Buy 500, -400 net.
Year 2. Sell 100, Buy 500, -800 net.
Year 3. Sell 100, Buy 500, -1,200 net.
Year 4. Sell 100, Buy 500, -1,600 net.
Year 5. Sell 100, Buy 500 - 2,000 net.
Kicking the can further down the road while accruing more dept isn't sustainable and I'm not sure what the end goal is. Spending 1b doesn't guarantee success (ask Man U fans) and if Chelsea can't get their shit together and get into CL regularly they will eventually end up in a financial dumster fire.
As for the players and the manager, I'm not optimistic in how it will all play out. Poch is a good manager and I'm sure he will turn things around from the mess that was last year, but I don't see how this squad gets beyond 7th, especially if Brighton, Brentford and Villa continue playing as well as they are.