Being dependent on merciless mercenary munchkins of some distant corporation is a burden no taxpayer-funded government should accept.
“The administration of the Dutch municipality of Waalwijk has switched to using the open source Postgresql relational database management system, replacing a ubiquitous proprietary RDBMS. "Continuing with the proprietary database would have meant a forced and costly upgrade to the vendor’s latest version", says Eric de Laat, responsible for HRM and IT at the municipality.”
FLOSS is the right way to do IT. FLOSS gives the lowest cost of implementation of a system because the efforts of the world to produce the software is shared. It’s that simple. Why accept a single source of software which charges an arm and a leg to use when you can welcome a shared product of the world and contribute whatever you feel helpful to the effort? PostgreSQL is designed to work for you not against you. Why pay for abuse? Use FLOSS for all your software.