I was asked by a customer what the upgrade costs were when going from SQL2008 to SQL2008R2?
Clearly on the express edition as each edition is freely downloadable, the answer was trivial - no cost. Previously a subsequent release was also a free upgrade if the "version" or "year number" was the same. Well MS marketing have clearly got their hot sticky little hands on this because (unless you have SLA) there is an upgrade cost. The pdf details are downloadable here: