Consumable item that restores spell levels spent that day

[Nibbens]

If you had to create a potion or oil that does as the title says, what would you price the restoration of one spell level at?

I came up with this calculation:

1) Wish allows the duplication of spells 8th level or less, so I used this as my baseline.
2) The cost of a wish spell is 25000gp.
3) The cost of a scroll of a wish spell is 3825gp (not including the component cost for wish)
4) So, the total cost of a scroll of wish to duplicate a 8th level spell or less is 28825gp.
5) Since 28825 in essence (and for our purposes) “creates 8 spell levels” we divide 28825 by 8 to get our cost of regaining one spell level which comes to – 3603.125gp.

So the grand total of a single replaced spell level would be 3604gp.

So yeah, what say you?

[Zaq]

Isn't this basically how a Pearl of Power works? I'm not quite sure what you're suggesting this item would do that's different from a Pearl of Power.

[Nibbens]

Isn't this basically how a Pearl of Power works? I'm not quite sure what you're suggesting this item would do that's different from a Pearl of Power.

This would be for casters who don't prepare spells, and the pearl of power is not consumable like a potion or a single application oil.

[Surpriser]

While not exactly the same, a pearl of power is quite a good baseline for the price.

It's consumable, so the price should be much lower. In addition, it should increase quadratically by spell level.

One could argue like this: Such a consumable is basically a scroll of "whatever spell you know". I would price it just like a potion of the appropriate spell level (if it is much more expensive, you could simply buy some scrolls instead).

To avoid spamming, it might be a good idea to limit the number of doses applicable by day (say, you can regain maximally the amount of your normal spells per day of each level).

[Zanos]

http://www.d20pfsrd.com/magic-items/wondrous-items/wondrous-items/r-z/runestone-of-power

[Hand_of_Vecna]

Your estimate is much too high. Pathfinder has Mage's Lucubration which restores a spell of level 5 or lower. A scroll of ML costs a mere 1,650gp (330gp/spell level). It aso restores any spell used in the last 24 hours so you could grab something you cast late in the day yesterday, but didn't memorize this morning.

It probably wouldn't be too far out of line to homebrew a version of ML for every spell level.

Edit: Actually to elaborate there isn't a remotely balanced direct gp/spell level equation because the value of spells increases geometrically rather than linearly, but based on Wish (9 for an 8), Limited Wish (6 for a 7) and Lucrabation (6 for a 5) and the Anyspell line we can extrapolate that a spell of your choice is worth a spell one level higher.