You might be wondering, "Should I jailbreak it or not?" Just jailbreak it. You'll save hundreds of dollars (Depending on how many and what apps you download).
You can easily jailbreak a 4G. I'm not sure about 5G (When it comes out) though. Apple probably is gonna come up with new anti-jailbreak ideas.
And oh - jailbreaking is not illegal. Cydia is not illegal. But Installous/Hackulous is.