An Amazon seller currently has Lifetime Maps for $49.40, including the $6.44 shipping charge. This is the lowest I've seen them in a while. Note that this is for the physical card with the lifetime code, it is about $30 more to get the code with online delivery.
Yes, there is discussion of that on POI Factory as well. When they offer those great deals it sometimes truly is for a limited time. The good thing is they, or somebody else, may have a similar deal sometime between now and Christmas 2011.