if a similar player has been sold for 650k then I think that you should report it because that is way beyond market price and it might be due to cheating. Your player is not worth more than 5k at most due to age and abilities. You hope that someone will misunderstand the value of the player and pay you a fortune. Your player will be very difficult to train to something better than an all star potential unless he is poorly trained and he should therefore not be sold for more than an allstar potential player with similar skills. But some, especially new trainer, misunderstands the concept of potential and believes that a player with MVP performs better than a player with allstar with same skills. I don't like it that managers tries to use this misunderstanding to earn money to their own team in a similar way than yours but you are free to put your players on the market for your own decided asking price so I can't report you for such unfair way to try to fool new users. This time I think that you overpriced your player too much though and that it won't even help to list him over and over again. Must be HoF or MVP players with a similar transfer deadline with a higher salary and lower asking price most of the time.
Had you not mentioned that a similar player was sold for a much higher price than you are asking for, I would not have written this message.