In the real world, if you walk into a church and point to a sucking chest wound on your friend, hand the attending priest a couple of hundred of dollars, and say "fix it", you are not going to receive much in the way of help (except maybe directions to the nearest hospital).
The same thing happens in Eberron. No matter how much gold you throw at the clergy, the fact of the matter is that most NPC
priests have no spellcasting ability, but instead have proficiency in History, Religion, and perhaps Performance for delivering particularly effective sermons. NPCs capable of casting divine magic are rare, and even if you do find one, none of them are in the habit of selling miracles.
Even for mundane medical care (using the Medicine skill), people do not turn to their local spiritual leaders. Instead, they head to the nearest House Jorasco apothecarion, whose attendees are only so happy to be able to provide them with quality medical care at a fair price.
When immediate trauma requires more potent, magical healing, House Jorasco is likewise the number one destination for adventurers and the wealthy. Their monopoly is based off the Mark of Healing, which makes them the preeminent magical caretakers of the sick and wounded across Khorvaire. Their proprietary dragonshard focus items allow dragonmarked members of House Jorasco to use their mark in versatile ways, beyond just the base powers of the mark. If you require a specific healing spell, and you don't see it on the list of spell-like abilities the Mark of Healing grants, odds are there is a dragonshard focus item that lets a dragonmarked Jorasco halfling use it.