Hello Bob,
Dear Colleagues: I've stayed out of this discussion till now. Here's my take:
1. ICANN should treat registrars alike, large and small.
Sounds good so far.
2. A large flat fee penalizes small registrars. A fee system based upon numbers of domains registered, with minimal fixed fees, is more equitable.
A large transaction fee penalises registrars with many names. Every registrar paying the same fee would be fair too and would meet your criteria no.1. It would however make it difficult for small registrars. The key is to find a reasonable balance between the two extremes.
3. More of ICANN's resources are expended upon the larger registrars.
I certainly have never used any ICANN resources to resolve an issue. In fact generally I make available my personal time to help out with policy development. I have never been contacted over a compliance issue either. At this stage there is no evidence either way whether ICANN spends more on small or large registrars. Perhaps ICANN could answer this question. I suspect that it may be some large registrars and some small registrars that cause most of the issues (ie size is not the issue, the behaviour of the registrar is the issue). Regards, Bruce