Yellow sided green cheek conure biting, need advise...?

I just picked up a hand fed conure from a avairy, he was the only one out of the group that was really fiesty, he's a very smart bird about 3 months old and is even trying to talk. The problem is he bites for no reason and sometimes really hard, he jumped on my 2 year old's hand and bit down which scared me. I called the avairy back and she said she would trade him no problem. I'm debating this, is there a way I can stop this behavior or is the bird just a biter? Any suggestions? Or do you think that I should go ahead and trade the bird in for a calmer bird? Thanks for the info.