I don't really find an issue here. Imagine the guy overbiding you to the last cent wasn't the owner of a player - would you still consider this unfair?
And such buybacking is usually not even for NT reasons. For that you overpay just enough to not grab other buyers attention, but not too much to get fined.
It's weird, but not illegal as I don't see anyone getting an advantage. At best case owner is losing a lot, as he won't be able to sell this gut for a while (daytrading rule).