Jack99
Adventurer
Show me any adventure any of them wrote for $1 and I'll buy it too*!
*Dungeon-a-day does not count
I do not think I can. Point is just that unless the work is truly exceptional, I would rather do it myself. And I think a lot of DM's feel the same way. It's part of the DM'ing part, one that I for one wouldn't be without.
Now, I am sure there are others out there, that wouldn't mind adventures tailored (to a certain degree anyway) to their campaign. Whether they will want to pay your fee and use your work is something only a trial run can answer (IMO), because people will have to see the quality of what you do.