It is a joke and it's mostly on anyone would would pay it, or for that matter... who could possibly pay that for a footballer? That number is just made up, market value... one man, who misses passes, flubs shots and gets injured - just like any man... be worth 500 m roughly? No man can be worth more than a team...
Reminds me of new car market value. New truck, 50k ... drive it 1 mile... uhhh no, now it's no longer worth 50k, maybe 40k
So the real cost is 40k and just 10k of hope-people-buy-at-this-price fluff....