BoVD has some alternate curses in the opening chapter.
1 of these increases a monster one age category.
Hello Dragons !!
Let's say you are a 1 HD 1st level dragon wyrmling, whatever color.
Not a dragonwrought or kobold (too bad).
Mercantile feat, and that theme-y thing that gives some more gold.
You can buy 3 castings of Bestow Curse, right off the bat.
So your baby dragon is now age category 4
During 1st level, you can afford 6 more castings = age category 10.
During 2nd level, you can afford ? more castings = age category ??
etc ... (this doesn't include the 1/level discounted item)
At will item = 3*5*2000*.75= 22,500 gp
Here's where things get interesting.
Advanced Dragons have virtual age categories.
So far as I know, there aren't any other "virtual"
age-type rules in Draconomicon or Races of Dragons.
I might be wrong, but it's a very limited application.
uses the virtual category, forwards and backwards.
Meaning the HD and the age category define each other.
EDIT --- jumped the gun on this part. The SRD doesn't have this.
So this appears to be uncapped.
And those Improved Spell Capacity feats look oh so yummy.
Anyway, it's T.O.
This isn't happening in a home game, at all
EDIT changed the 2nd level 7 and 17 to ? and ??