Wholesalers you should usualy do if its in your normal adventuring range. A few free silver from harvesting is never bad. :)
Workshop tasks are hit and miss. With most items you will get more money back then selling to a NPC Merchant, but less then if you sold to a player. This is a good way to grind items to level, but because they may require sub-par quality items it does not yeild the best exp or money. Defently look at your tasks, if its a higher difficulty and you wont lose money I strongy suggest doing them. Unless your an Alchmeist or Provisoner, you proubably can make many times more then you can ever sell and this is a good way to get the exp, and more money without flooding the market. Note: Do not do rare items, or overly complex tasks. Your paid based on the teir, not the item itself. So making a 2 combine common item pays as much as a 6 combine rare. Pick your tasks, if its not one you like, wait and change it.
P.S. Quality Matters, If they ask for App2 then make App2. App3 will not count. If they ask for App3, make App3. :)
Edited, Fri Jan 21 11:32:40 2005 by Corison