Let’s just say the money would need to be that big to lock him in that way- and to pay out of existing contracts. Look at what Puma has admitted re logo exposures- 358mil. That figure sounds pretty accurate to me based on what I remember was going on in the old days.
It is also interesting to look at the IAAF website as an example. Largely in anticipation of what Bolt might do, they scored 300,000+ unique visitors per day. The next year it was above a million. These are big value numbers!
Perhaps this will lead to an extension/renegotation of his Puma deal, which would be kept out of the rest of the negotiations.