If a community currency is economically viable, then the economy it develops can certainly fund the operation of its own money.
However, multiple currencies will be prevalent, for the same reasons that colour is generally preferred to monochrome. Platforms that enable multi-currency operations will generally enable the operations of any useful currencies.
Hence monopoly processes that enable extortionate charges will not be feasible, and long-term profit generation is very unlikely. This renders the normal market driven development process unlikely, since the end users can run their own systems independently of the original investors. It's impossible to charge for something that's freely available -- toll booths don't work when you can build a road anywhere.
The most common form of cc is likely to be the LETSystem. The core characteristics of the LETSystem -- a service organization, using the normal unit of measure, charging no interest, and minimal service charges only, with appropriate bank-like privacy for users -- were chosen to meet the most general needs. See the LETSystem Design Manual for reference.
The likely proliferation of this particular design provides an opportunity for a particular program of development and development financing, as described in Section 5 of the Design Manual.
The base funding for community currency projects for perhaps 5+ years can (in theory, at this time) be derived from a particular LETSystem revenue stream.
The communities presently implementing this model, developing practice from theory, include
back to community currencies -- on to community way