I came here to suggest fees dropping as volume rises, but of course it's already been covered! All I can add is that you're not even factoring in the cost of fi

I came here to suggest fees dropping as volume rises, but of course it's already been covered! All I can add is that you're not even factoring in the cost of finding a competent developer and paying them to make that happen - small nonprofits usually don't have a developer on staff, often just a volunteer or two who may really just be WordPress admins.