It will become profitable when price is higher than current price. Ethereum is example for mineable coin that gives you periods to mine before price increases together with difficulty.

Ethereum one year ago has very low price and SUMOkoin can repeat the same growth. It is more potential with its low cap. This coin is a hidden privacy coin and today I see Deep Onion rose a few hundred percent after it is listed on TradeOgre exchange.

Ravene coin (RVN) is another good example for mineable coin. Mine such coins when you can enjoy low difficulty and less miners because of low price. Miners will join more when price rises but at the same time difficulty will soar too much. Price and difficulty have correlations and mining requires strategy and patience to get big profit.