I like the idea but I'd prefer a personal 'energy' sacrifice. Like, taking Hit Point damage or Stat damage to power your spells. Something like that. Sadly, 5e doesn't include that kind of thing.
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Quite a few of them have not so arbitrary legacy reasons that no longer apply. 5e chromatic orb takes a 50gp diamond & allows the caster to choose the damage type but that's no longer meaningful in ways that it was in some of the past editions....The frustrating part is, many spells are gated behind seemingly arbitrary component costs that require the GM's benevolence/judgement to grant access to a big part of your class powers......
No most of those spells are kind of powerful. I just tell my players if they in a big town to convert GP to material component.
I haven't update the spell cost list but
5E Spell Cost Ver 1.2 - Updates
I roll to see if the town has it. The larger the town/city, the more likely. Diamonds are also easier to find than say the special incense and ivory strips for Legend Lore. Other times I handwave it. This last session the sorcerer needed more special chalk for his teleportation circles. They were in the main temple of Mystra and had done the temple multiple important favors, so I just told him that they give him enough to bring him up to 10 uses. No roll.I'm playing a cleric in Descent into Avernus and we are, currently, 12th level. There are a plethora of useful spells on the cleric list but many of them require materials like, "diamonds worth 1000gp", "rare incense worth 400gp" etc...
I'm not sure if other people have played this campaign, but we haven't had the time or resources to acquire thousands of gp worth of diamonds.
Meanwhile, in another homebrew game, my wizard needed to buy a 5kgp chest for Leomand's Secret Chest and the GM just hand-waived it. "Oh yeah, there's a guy in town who makes those
The frustrating part is, many spells are gated behind seemingly arbitrary component costs that require the GM's benevolence/judgement to grant access to a big part of your class powers.
In one campaign, I feel frustrated and my choices are limited meanwhile, the party monk has access to all his abilities all the time. I see it makes sense in the context of the campaign, though. What use do devils have for piles of diamond dust?
On the other hand, the game where my Wizard had free access to unlimited resource (provided I had the cash, obviously), my character felt much more powerful. Sometimes, too powerful. Wizards are probably more dependent on GM grace given their need/ability to copy spells.
I can really see a DM saying, "I'm happy to give them access to one use of Greater Restoration per level" or "1 raise dead per campaign".
In the occasional game I run, I like to drop it as part of treasure but I don't try to be specific: "In this lab, you can scrounge 500gp worth of material components." then I let the player decide what they find.
As a GM, how do you dole out components and resources to your spellcasters? Do they have to quest for them? Are they readily available? Do you even think about that?
In my case, we never had to deal with anything more exotic than some diamond dust for stoneskin, and the region the campaign took place in had no settlements above a certain size (in one case, the setting was Lamordia in Ravenloft, so there was no opportunity to find a bigger settlement). Since I didn't want to semi-arbitrarily block the casting of some spells, it was therefore a simple gold exchange.
As far as I can see, material components do two jobs: they add some flavour to spellcasting, and the expensive ones add some balance to more powerful spells. Except that I don't think they do an especially good job of either - the balance of spells is already fairly wild, so adding expensive components doesn't actually help; and most spellcasters now use focuses to skip using expensive material components anyway.
