DB none of us is a modder.We are just dedicated members .We help him but in a limited way by providing feedback and acting as testers when we have pcs that actually can play his mods-releases with sufficient specs.
As for the fee better ask him because he´s the one who decides and I am just assuming that for the time being he prefers having a limited member base rather thna going all out for a huge crowd which would overtax his physical resources.