On and after January 1, 2000, a public provider shall offer service at a price or rate to each subscriber which is either (1) equal to or greater than the price or rate for comparable service of competing private providers or (2) equal to or greater than the incremental direct and indirect costs of providing service to such subscriber. If, however, such service is required by state or federal law or regulation to be offered as a subsidized service, the funds to cover any deficiency in such costs shall be identified in the full cost accounting of such service.