I think there should be some sort of a directory available for paid modifications .... I do feel there should be a fee for businesses/coders to take part in the listing. ...
Um.... No! We paid enough for vB in the first place. If anything like this, there could be an area set to advertise the (Corporate) mods that you need to buy, but it's not a good idea to encourage everyone else to make a profit.
I can go either way. I think it would be an incentive for people to spend more time making great hacks that are useful to all of us. On the other hand, I imagine it will be the beginning of the end for free hacks.