If all I had to do was one measurement of an expired course and submit only that data (no new map), I could charge very little.
As a certifier, if all I had to do was review one set of measurement data and then change the measurement and expiration dates on the certificate, I would also charge much less.
We could greatly reduce the cost of "re-certification" of an expired course if we take a careful look at what parts of the certification process aren't really necessary for expired courses.