I suggest you buy the Dash mining contract. Bitcoin is very very difficult to mine today. The bitcoin contract will easily be cancelled due to the difficulty increase and constant maintenance fee! And other altcoins difficulty also keep rising rapidly. Dash mining difficulty is relatively stable comparing to those coins.
This is only my suggestion.
If you decide to buy a contract on Genesis Mining, you will get 3% discount using my promo code: S6ew4u
Thank you :)