They wouldn’t have bought $100 worth of product if the deal weren’t offered, because they didn’t have $100 to spend.

If they couldn't borrow $100, or get $100 from any other investor, that just puts you in the position of being an investor, and even then the difference between bradfa's version and mine is simply when you became an investor, not that you became one.

Again, this is not a cheat code: if you sell $80 of cost for $100 of stock, the stock you now own can go up or down, and if you overvalued it then down is the more likely direction.