kitcik
Adventurer
The truth is that the economy in D&D, if you put real thought into it, simply doesn't work. This means the DM has to house-rule any time something will have true economic impact that could cause the PCs to be out of whack on a wealth-to-level ratio basis. Not to say that the DM has to follow the wealth by level guidelines in the DMG, but whatever they are setting the CR in relation to, they have to monitor anything that impacts the economy that would throw that off.
Sorry to quote myself (yes, the ultimate forum faux pas), but after 4 pages of discussion it all comes back to this.