Although it's seems not be directly relevant to the OP's question, I'd like to point out that npcs are treated differently. Here's the quote from MM5, page 7, 'Typical Treasure':werk said:Here's a quote from the SRD: "Also use ECL to determine starting wealth for a monster character."
A creature that has been advanced by class levels has treasure equal to an NPC of its Challenge Rating, not its ECL.