I think op means who would design the method(interface) that turns free mods-->mods for $$, and does it in such a way that free mods fade out, and the only good mods cost. Could be wrong though.
On a more personal note, I respect, enjoy, and am grateful to those whose mods I use. However, I would hate to have to pay for them. Especially when half the mods I try I end up not using. I would not buy any mods, and I think it would ruin the whole idea that is the modding community. Modding to me is something done by fans, for themselves and other fans. Throwing money into the equation just kicks it up. Plus, if a modder is truly talented, he may be picked up by a company, or start his own etc etc. Modding seems more of a path to that, or a hobby, then a business. That's just this mod users take on it, and having never created a mod myself take it for what it's worth