There is no airport equipment required for WAAS. You are probably thinking
of LAAS.

But, if the airports don't meet current FAA standards for IFR runways and
taxiways, then there can be modest costs for runway markings, or
significant costs to bring the pavement into compliance.

It is a very complicated mix, but since the airports are owned by local
government, they should have a knowledable airport engineer on the airport
staff who is already up to speed on the airport advisory circular
requirements, and what the FAA regional airports division expects.

wrote:

I have the ear of some local government development people, who are
contemplating upgrading some airports. Money is tight, so an ILS is
probably not under consideration. So, I want to recommend to them
checking into a WAAS installation. Does anyone know what the prices of
such equipment for an airport are, which companies are selling them,
and how much it costs to get the FAA to then create a WAAS IFR
approach?

Sincerely,

/iaw