The percentage which you mention for buying and selling is not understandable because sometimes you buy a coins and think that it will pump during Bull season but actually it dumps and all your money become zero so its not important that when you buy at lower price you will definitely get huge profit but it totally depends on the type of coin which you pick for you future success. You have to keep concentration on the price of some trustworthy coins that have surety that they will pump whenever the market become pump so then you can have greater possibility of earning more revenue. Lower price is not just a thing which can give you profit but instead of this there are more others rules which you should have to follow for profitable fortune which you should learn first.