Well, I dont really think those are "cheap", price of a coin itself does not make it cheap, its about market cap in my opinion. The coin can cost 500$ or 1$ with same marketcap, but that doesnt make a 1$ cryptos growth potential higher. In this case, buying 500 coins worth 1$ is same as buying one coin worth 500$.
But to answer your question, i think best are:
-ADA
-XRP (if they succeed in what they want)
-NXT
-ARDR
Marketcap is one of the reason that cheap altcoin can go further higher or just shit coin.
In this topic you said ADA, i have heard about this and there are many good support behind. With that, i think ada can go higher in price.