A scenario I've seen is "weeeeell, your first year is up; our ToS says we can change the pricing at any time, so it's now $1000/year. Don't like it? All right,

A scenario I've seen is "weeeeell, your first year is up; our ToS says we can change the pricing at any time, so it's now $1000/year. Don't like it? All right, but remember, the domain is ours. You're completely free to start your business anew on a completely different domain; how about $10/year for that new domain?" I would not trust such scheme _at all_ - it is much, MUCH safer to buy the domain and set up the CNAME yourself.