For two years Israel has been handling "allocations" in a free fashion. Lately, as I am sure with everyone, the burden of registering IP class C networks, domain names, contact people, inverse domain names, and routing updates is taking more and more of our time, personnel and our national DNS primary CPU.
Naturally you took this on on a purely voluntary base (nobody forced you to do it). I would consider it to be very improper to start charging "users" without a clear consenus in your country on how the various registration issues etc. should be handled and if they want your organisation to continue with this role in the first place. The current German solution seems to be very good and would seem to avoid the obvious conflict of interest issues that immediately arise if non-neutral organisations provide these services. Simon