Its a great deal at 10 bucks per year if you average the $19.99 over 2 years.
However the renewal at the 3rd year for $19.99 is on the high end. They are counting on people being compliant and just renewing at $19.99 thereafter. They are probably right in that assumption because most people can't be bothered to change registrars after, especially if they buy hosting or something on top.
Personally I would rather pay 11.99 per year at Canspace or use the WHC discount club and not have to worry about paying $19.99 thereafter.