it wouldnt matter if his buy now was 10billion, people will only pay his current worth, which is determed by the players / market not EA, they only reduce the max buy now price when the player has been selling lower than it for some time.
The same way they raise the max buy now price of a player if hes extinct for ages.
For example the new cards just come out, Xavi was at like 10mil day one, if people are silly enough to pay that he will only be worth about 800k by thursday, the players decide that not EA, its supply and demand