False Focus is sort of in the ballpark.
False Focus is close. But I thought there was one that directly let me sacrifice gold and other valuables for costly material components. Like instead of a diamond worth 5000 gp for raise dead I could instead pay 5000 gold (plus a little extra like 10% more) when I cast the spell.
Invested Magic is what you are looking for. It is from Council of Thieves. It is in Hero Labs but I cannot locate the online version.
Specifically it's from Council of Thieves #6: The Twice Damned Prince, page 69. It is available to followers of archdevil Mammon.
Invested MagicSpells cast using this feat pay the wages of Mammon and forgo their more mundane costs.
Benefit: You may satisfy the material requirement of any spell you cast with valuable coins, gems, or jewelry rather than the normal component. For spells with material components with no listed value, valuables worth 5 times the spell’s level in gp may be expended instead of the usual components (5 gp for a 1st-level spell, 20 gp for a 4th-level spell, etc). In the case of spells with components that have a listed cost, you may expend valuables worth a number of gp equal to one and a half times this cost (thus, a spell like commune with material components costing 500 gp could be cast using valuables worth 750 gp). Only coins, gems, jewelry, and other similar objects of obvious worth can be used to replace other material components using this feat. The value of these objects need not match the required cost exactly, but they cannot be less than the required costs. Should valuables of greater value than required be expended (likely when employing objects like gems or jewelry), the extraneous gp value is lost, consumed with the rest of the object. The only exception comes in the case of spells with material components that have a listed worth. When casting such spells you may expend double the components’ gp worth in valuables to cast the spell as if your caster level were 1 level higher. This effect only applies to spells with components with a specific gp value. Any expenditure beyond double the gp value grants no additional benefit.