1) There is no limit on a player value.
The worst player can be set to market with 1M$ starting price, and be paid that much.
Please understand that you are expected to report such transfers. All transfers must be fair, and all transfers must happen at real market prices. Your example is clearly an overpriced transfer, and such transfers will be adjusted.
You are speaking on something that is clearly a over/under bid price.
But, there are mid-auctions that will pass.
It is a fact that day-trading exists, which means that the definitions for that automatic tools are not that tight.