It's wolf and pit who are the cheapest. Wolf can win matches just by spamming his up and side smashes. Pit has near-infinite recovery. Wolf's non-smash moves do tons of damage. His recovery move has no buildup. His side-b goes at an angle making it hard to anticipate. Pit can spam his side-b for almost forever. In other words, Ike is the least of your problems.
don't forget, Ike's side B is easily spammable, so theres a problem. its really strong too uncharged. All three can be annoying. Though spamming moves can be easily countered by my Marth.