It's not cheaper than buying one (just like making magic items with Enchant an Item isn't cheaper than buying them); the advantage of a ritual scroll is that you don't need to be a ritual caster to use it and it's faster (casting time is half the normal casting time of the ritual), but the disadvantage is that you're paying the cost of a ritual book for a single use of a ritual (and you have to pay the component cost either way). It would cost 680gp for Sariel to make a scroll of Raise Dead (or buy one); to use it to raise one of the PCs would take another 5000gp of components, because we're paragon-tier PCs.
Sariel is a very extreme case of a 'lazy warlord'; she has... two powers that attack directly (both because she didn't have any options that would have avoided that), low strength, only a +2 weapon, and no expertise. But she can grant melee and ranged attacks; I expect her default combat move is going to be Commander's Strike with Durn.
Oh, I think I'm going to roll with what I've got.
