Once you got profit then just stop it. Because if you change your profit to a percentage you could control your greed. 
Yes this is so suburb technique. If you want to control your greed, it is not that much difficult. Just need your mind which will help you and you will be free from this awful nature. Greed is a bad instance that is eating you up from within and make you a selfish person that doesnt care about anything else other than greed. Contrail your mind and control your profits, there you are.