>"The marginal cost to produce data (or software) is almost nil"

Nonsense, GIS data typically found in municipal datasets requires going out to field and physically locating items such as underground utilities and stream edges, as well as, verifying data pulled from other sources.

The cost of reproducing that data is low, but then again, the cost of unlocking a stadium is equally low...roughly equivalent to the cost of quality assurance measures one might take before distributing a copy of municipal GIS data, or the cost of maintaining adequate bandwidth to distribute data sets the size of a county GIS database containing 6" resolution aerial photography.