How well has giving out rituals as a reward worked out in your campaign?
I play things a little different with rituals and magic items:
Magic item super-stores are fine with me, it even makes sense.
In a high magic style dnd world, why wouldn't there be the equivalent to a WoW AH? It could be regulated by genies, wizards, gawdz or whatever.
Embargoes, sanctions etc can all be good hooks for adventures to boot.
In any case, it is assumed in most games of 4e that characters with money will be able to buy whatever item they can afford. Some people ban specific (broken?) items, but the idea of magic item shops that either have access to all types of items (or are "magic" magic item shops that have just what the character is looking for) seems to be a pretty common ideal.
But the rituals... There are so many of them now, and so many of them radically alter what kinds of stories and world events can happen, I severely restrict their availability.
They can not be traded or taught, only learned through pilgrimage to special areas such as shrines, relics or bearing witness to random cosmic events. Some are common, others rare, some secret, others at the center of famous cities.
I'll sometimes include a chance to learn a ritual in a dungeon or lair, or wherever something exotic might be found. I don't count it against the parties treasure, I just add them in as an alternative reward and to stoke the players interest.
I intend on eventually tacking all of the basic-burger rituals to specific cities and so forth in my campaign - hopefully encouraging/creating a pilgrimage motive for adventure or player generated side quests.
edit: Also, I substitute components for gold all the time.