But to be able to gain extra money by such means is simply wrong, falsly inflating the price, this action means you have paid more for him than you was meant to under fair and uncorrupt circumstances. As for recommending the strategy to anyone, it happens, alot, so people are doing it, recommended or not and gain financial benefit for doing so, otherwise it wouldnt be happening.
However you look at this, if a player would have been sold for say 500k, without owner interference, but ends up getting sold for 750k because of that interference, means you have paid more than the true market asked for him due to insider bidding.
I would punish players who remove their players in the same way they are punished now, they have to pay, either, the estimated player value, or the current price he is up for on the market, that way they would lose money for changing their mind. Another way would be to take the tex off of them, which is less harsh than full price, both systems would offer a consequence for the action.
I agree with you that you shouldnt be allowed to buy back players at all, I think once they are up, they are up, but I also think you should not be allowed to bid on your own player under any circumstances, but if the game is to allow that, atleast create a system that only allows it for the right reasons, and not to gain more money in a false economy, bidding situation.