Aside from the whole cantrip discussion, this is nice to see. Seems like scrolls don't have set prices but are instead the "rarity" thing that still makes no sense, other than the general idea of how often you see it. Was there a "rough" price list per rarity somewhere?
There was in the last playtest. I assume it will be updated for the DMG. I think rarity is meant to correspond roughly to character levels. This table of rarity to spell level for scrolls is a good hint for what character levels items are appropriate for.