LogMeIn Hamachi has two versions: Free and Premium.
You can find a comparison of the differences between the two here: https://secure.logmein.com/products/hamachi/advantages.asp
You can find pricing for Premium here: https://secure.logmein.com/products/hamachi/pricing.asp
Both Free and Premium licensing are per Hamachi account. A Hamachi account consists of the 5.x.x.x IP address. So in effect, licenses are per computer as you can only have an IP on one computer.
At this time, licenses are static. They do not renew on their own, and the notification of license expiry is done on the client side, i.e., the computer it's assigned to. In the coming months, Hamachi's licensing will change to a subscription model, with online license management and deployment.
If you are premium you always can in war soulstorm (hamachi net)