I was thinking somewhat the same thing. You know the adage... if something is too good to be true...

However, you own the domain once you pay for it, so worse case you'll have to relocate it by finding another hosting company, transferring the DNS, and then republishing the site. It might be down a few days but in the end it will be seemless to the public.

You'll have to read the fine print of course... it might say "first 3 years free but your contract is for 10 years at $x.xx". Don't know.