To simplify the creation and purchase costs of consumable magic items, we looked to what the Pathfinder Society does, and have taken their stance on the issue. This sets a minimum cost for the item that does not vary by the user or creator.
In Pathfinder Society, and in the LPF world,
- "All potions, scrolls, wands, and other consumables are made by clerics, druids, or wizards in Pathfinder Society Organized Play. The only exceptions are spells that are not on the cleric, druid, or wizard spell list. For example, a scroll of lesser restoration must be purchased as a 2nd-level scroll off the cleric spell list and may not be purchased as a 1st-level scroll off the paladin spell list. If a spell appears at different levels on two different lists, use the lower level spell to determine cost. As an example, poison would be priced as a 3rd-level druid spell instead of a 4th-level cleric spell. All potions, scrolls, and wands are available only at minimum caster level unless found at a higher caster level on a Chronicle sheet.
- For the sake of simplicity, there is no difference between an arcane and divine scroll or wand in Pathfinder Society Organized play. Thus a bard and cleric may both use the same scroll of cure moderate wounds."
So, that clarifies it fairly well. Lowest level of (Cleric, Druid, Wizard), or if not in there, lowest level of (the rest of them). And the second rule is more useful. Don't bother with arcane or divine versions, it just works.
As to wands, I believe all wands are purchased fully charged at minimum caster level unless:
- they were sold to the Mystic Pearl by another character partially used,
- they were commissioned.