Inverse Metamagic [3.5 feats]

[qwertyu63]

This was just a random idea. It's likely horrid, but I'm putting it out there.

Pricey Spell [Metamagic]:
Benefit: An pricey spell requires a diamond worth 100 gp per spell level as an additional material component. A pricey spell uses up a spell slot one level lower than the spell’s actual level (The cost of the diamond is calculated with the pre-reduction level).

Minimize Spell [Metamagic]:
Benefit: All variable, numeric effects of a spell modified by this feat are minimized. Saving throws and opposed rolls are not affected. Spells without random variables may not be modified with this feat. A minimized spell uses up a spell slot two levels lower than the spell’s actual level.
Broken as hell.

[Craft (Cheese)]

You should specify that this doesn't change the spell's actual level for the purposes of interactions with effects like Arcane Fusion, else you get Sanctum Spell shenanigans, except worse. Even with that though, these feats (especially Minimize Spell) are still really, really strong: Their best uses are with spells with damage that have a strong rider, like Darkbolt or Boreal Wind.

[Kamai]

Fell Drain minimized Magic Missile. Edit: I was wrong. It's a first level spell, from what I could find. Still very scary.

[qwertyu63]

Fell Drain minimized Magic Missile. Probably the scariest cantrip you'll ever run into.

Woah... OK, minimized is broken as hell. Got it. This is what happens when I toss out my random ideas.

[gr8artist]

I like the idea, but there's a problem with negative metamagic.
Applying metamagic alter's the spell level regardless of the metamagic's actual effect on the spell. This isn't a problem with positive MM's, because no one would use a higher level slot to cast a lower level spell. But with negative MM's, you add in the possibility of someone making a worthless change for full benefit. So, any negative MM's will need to specify that they can only be applied to appropriate spells.

Flash spell
You sacrifice the duration of your spell to make it easier to cast. The modified spell must have a duration greater than 1 round.
The modified spell's duration changes to "one round". A flash spell takes up a spell slot one level lower than normal.

Dull spell
You sacrifice piercing power for ease of casting. The modified spell must be one which checks against spell resistance (SR: Yes).
The you take a -5 penalty on caster level checks to overcome spell resistance with the modified spell. A dull spell takes up a spell slot one level lower than normal.

[TuggyNE]

Dull Spell is a no-brainer if you expect to be fighting creatures without SR, also known as the majority of enemies up to mid or high levels.