with a capital of 17 bitcoin? you want to get 7 bitcoin. it may even be more than that, but you have to have a commitment, my advice BTC that you use for the new coin trading, because of the new coin trading percentage we get to be 2-7x from the initial price. Do not ever be tempted kind of gambling! 
I think more and more capital would be more easy to get a lot of advantages, but the risk would be even greater, perhaps trading would be better for this