At op you have 2 - 3 cent power mine just don't get a lot of cards.

IF COINS GO UP YOU HAVE 2 CARDS MINING THEY MAKE MORE.

if coins go down cards are cheaper add 3 cards with the money you held back..  Then you will have 5 cards.

So you flatten your risk a lot this way.

Any one telling you any other advice is disregarding your cheap power. Which allows you to flatten risk and make a profit. If coins go up or go down.