Metamagic Components

Recently I wrote two articles for this site, Spell XP Cost Variant and Magic Item XP Cost Variant. I have to admit that they were inspired by this:

Metamagic Components, an article originally published in Unearthed Arcana, includes a fantastically exhaustive list of each basic spell in the game along with an expensive, optional material component that can be applied to it in order to apply a certain metamagic for free. For example, you can spend two +3 arrows to cast magic missile as empowered. You don’t even need the metmagic feat to use these material components, but take care to watch your wallet - the costs can add up! Check it out at the link above.