Exploiting a Houserule...

[Godless_Paladin]

So, one of my DMs (the one that didn't move away) has a houserule that all metamagic and the like only increase spell level by one per modifier (i.e.: a maximized, enlarged, quickened fireball would use a 6th-level spell slot). Any ideas to utterly break this system?

EDIT: Okay, maybe a clarification is in order. I need a build idea (20th-level gestalt) that can take the most advantage of this system. I will be going epic with this character. Stats are 18, 14, 15, 17, 14, 16 ([1d6+12]x6).

Are you sure this person ought to be writing a group's houserules?