I’d always assumed that moderation for an identification wiki would be done entirely or almost entirely by volunteer users.
I think the main benefit of having an ID wiki will be that the bulk of it only needs to be written once, and then it can help train many new identifiers, far more than were required to write it in the first place. Yes, there’s an up-front investment of time from current identifiers, but I think it will pay off big in the long run. I don’t really see any other plausible way for recruitment of new identifiers to be increased so much with so little investment.
Some years ago I made a specialized ID guide here on the forum. I’ve been tagged a dozen or so times by people citing the guide as a source used to arrive at their own ID, and I assume that for every time I was tagged, an order of magnitude more IDs were made without mentioning how the ID skills were learned. So, I think it has more than paid off in terms of my time spent vs. new identifier time it enabled, even with such limited exposure. It has also helped me - the sad fact is that I forget things, and having all my notes about identifying orbweavers from the underside organized properly has helped me maintain my ID skills in that area, vs. other specialized ID skills where I never got around to writing up everything I noticed and I now don’t remember why I made certain IDs.
So, cost vs. benefit, I think the benefits will outweigh the costs by a large margin, long term.