Paranoia of getting hacked

So yeah, i got hacked a few weeks ago nothing too dangerous, but it still had me abit shocked. I called Blizzard right away and they we're able to give me my account back in about 2 minutes. Im very grateful for that. I cleaned my pc from 2 keyloggers, and reformate the whole comp.. However, i now suffer from paranoia, that i might get hacked again.

So i was thinking that i'd buy that authenticator thingie, people say it's a really useful tool. It prevents you from all sorts of keyloggers. What i want to know is simply, is the authenticator worth the low amount of money? Does it secure your account, and would you advice me to buy one?
Because this paranoia isn't that great to have, (Yes i know that i play alot).

So simply, is it worth the money? If so, point me to a direction where i can buy it.