[narf poit chez BOOM]

Level/Treasure table in the DMG, page 54 in v3.5. Breifly:

Code:

---

Level | Expected Wealth Gain | Treasure From Encounters | Treasure Per Character

1st   | 900                  | 3,999                    | 1,000

2nd   | 1,800                | 7,998                    | 2,000

3rd   | 2,700                | 11,997                   | 2,999

4th   | 3,600                | 15,996                   | 3,999

5th   | 4,000                | 21,328                   | 5,332

---

Expected Wealth Gain: What the character should gain while reaching his next level
Treasure from encounters: This is the average treasure value from table 3-3: Treasure Values per Encounter multiplied by 13.33 encounters.
Treasure per Character: This is Treasure from Encounters divided by 4, the expected party size. The amounts are rounded to the nearest gold piece.

This goes all the way to 0.8 million for 19th level characters. Obviously, D&D is not an exercise in applied economics.

Wether you want to follow this table or not and how closely is up to you.

Additional note:
'Given the hoardes of monsters and heroes running around, any rationally constructed D&D world would be de-populated within approximatly one month for the general population. Survival of higher-level beings is indeterminate. Given that the D&D power level continues to infinity, reality would probably be destroyed at an indefinite point after it's creation, unless beings of all power levels were also created, the result of which cannot be determined.' - Narf.