As someone who has been involved since 1993 with law.com (and others) it is clear that there is a fixed cost to running the .com TLD.  However, given the large number of names, that fixed cost is spread over a large number of domain names.  Allowing for an increased price and annual increases will only serve one entity - the registrar.  If that is not clear, put out the .com TLD for competitive bidding and see how many entities will bid at a lower price.

Thanks