Expensive Material Components Alternative => Rest Mechanic Houserule

[Necrosnoop110]

How would it work out if one were to swap out 5E's costly material spell components for a cool-down mechanic based on requiring long/shorts rests to cast that spell another time? The more expensive the material components the more rests required to "recharge" the spell. Especially since as you level most campaigns have more raw coin that they know what to do with.

Something like the this:
<50gp = 2 short rest
50-100gp = 1 long rest
100-500gp = 2 long rest
500-1000gp = 3 long rests
etc.

For example: Normally the 4th level Stoneskin spell requires Diamond dust worth 100 gp to cast, which the spell consumes. So under this houserule we dispense with the diamond dust, however after the first time you cast it you must take 2 long rests until you can cast it again.

Obviously this is unpolished but how do you think something like this would pan out?

Thanks,
Necro

[Anymage]

First, it affects different classes differently. A prepared caster can just prepare something else in that slot tomorrow, while a spells known caster is down a slot until the downtime passes. One cost is much more significant than the other.

Second, while spells like stoneskin that are designed for use in combat will be messed with, there's a wide bunch of spells that are designed for downtime use and the gold cost is to reflect their influence on the overall game world. Downtime spells care a lot less about cooldown times, so these spells will present their own issues.'

Second-point-one, a small number of spells like Animate Dead require casting daily, or spells like Teleportation Circle require multiple castings on subsequent days in order to have a permanent effect. These spells/functions straight up stop working if the spell goes on cooldown.