You are incorrect, there are some carriers that do have it for free.
haha I saw he had t-mobile. He doesn't have sprint. So therefore AIM isn't free. (excluding ramble and oz mess because those are so bad that they don't count) duh
You can mess with the free stuff, become frustrated and then purchase JiveTalk or you can just start with the best to begin with. You'll find the consensus on this forum is that JiveTalk is the best IM software out there and works with all the major IM services. You can try it for free.