I couldn't agree more with posters that have questioned why 14 pages have been devoted to this topic!!
There is no widespread demand for a reworked, realworld economic system in 4e.
Just because a handful of posters are screaming for the ability to bargain better deals for their equipment doesn't justify WotC publishing a splatbook on economics.
Earlier in the thread, people began to reason out what would have to go into a book or discussion about setting prices based on supply and demand, and, personally, the splatbook would be ridiculous, talking about things like goblins seizing iron mines and what not.
If the big problem is you would like your high-Charisma statted character to be able to bargain better deals, then
1) talk to your DM first and make sure it will be worth it for you to build a high Cha character for that purpose (heck, you don't want to do the build if the DM isn't willing to allow that option in the first place)
2)When you acquire an item or create an item, talk to your DM about spending/wasting several days of game time while you go around the city/sending portals/etc bargaining for the best price. Realistically, even just drumming up business in the nearest town might take a whole day to play buyers off of one another, travel throughout the city to get to this buyer or that one, especially if they are nobility. In the meantime, does the rest of your gaming group want to sit around and wait for you to do this? If they do, great - now you've got yourself the perfect scenario to work some skill challenges etc etc. If they don't, if they are more content having tossed their loot to the peddler for 20% of its value and are eager to get back to bust some orc-ass, you may have a gaming group problem.
3) Either way, NOTHING in the rules says you can't do this! I personally don't want a DMG that dedicates 20 pages to different fleshed out examples of skill challenges. The seven pages or so and five examples was just fine. The rules to create skill challenges are the most important part of that section anyway.
I just don't see what people are fighting about. There's nothing broken in 4e's economic BALANCE rules.