Squire James
Explorer
I'd consider offering Ritual Casting to all characters for free, but requiring training in the key skill to actually master a particular ritual. For instance, only characters with trained Heal can learn the Raise Dead ritual. More rituals will be available to classes with knowledge-heavy class skills, while virtually any ritual can be available if someone wants to spend a feat to gain skill training (either directly or through a multi-class feat).
I also favor changing the cost structure somewhat. Perhaps a component system that specifies a key skill and a tier value, with each casting of a ritual costing a single component of the ritual's or the target's tier (perhaps more for certain expensive rituals, but nothing costing more than 10 of them). Then you can determine the gold value of each component, or even assign different names and/or costs for components for different skills. This is not exactly simpler, but it is a bit more flavorful.
I also favor changing the cost structure somewhat. Perhaps a component system that specifies a key skill and a tier value, with each casting of a ritual costing a single component of the ritual's or the target's tier (perhaps more for certain expensive rituals, but nothing costing more than 10 of them). Then you can determine the gold value of each component, or even assign different names and/or costs for components for different skills. This is not exactly simpler, but it is a bit more flavorful.