Why go for those shit cards? They draw low power and have low hashrate output, and if electricity is free for you, you should buy heavy cards with high power and high output. Go for 1080TI or 1070TI, anything less then that is waste of money in my eyes.
those cards have doubled in price when bitcoin (and other crypto) increased and have yet to decrease to mirror the current prices of crypto. buying them right now is wasting money.