I didn't say it was ethical :P I just said it wasn't unethical :P It is very hard to judge the price of some players (the price they could sell for). So in my example, with the 18yo 4k salary Superstar, some times it could go up for sale for over 500k, so rather than do that, I thought I would put him up for 1k and let people bid on him. It was only on 20k near the end of the auction time, and any manager would be mad to let such a good player go from their team for such little value.
Are you honestly telling me that you wouldn't have bid the player up 1k to ensure you keep him? You aren't harming anyone else by doing it, if you bid up your own price, and the price is still reasonable then others should still feel free to bid on it. If you bid it up too high and other players don't want it anymore then I still don't see how it is unethical as the end result is that you get the player back, and there is a fee and other side effects.
I think it is a valid strategy in dire circumstances.