I don't think it is unethical. I put my draftee up for sale the other day, he had superstar potential and 4k+ salary and was 18 years old with a good height. I listed him at 1k starting price, and 2 minutes before the transfer deadline he was only on 20k. In my opinion that was way too little for him, and so I outbid the guy to make sure I kept him, he is worth a lot more to me on my team than getting 20k, and considering I get 97% of what I bid back it barely cost me anything to keep him.