Custom Item Creation - Caster Level increases

[muzzilla]

Trying to figure out the creation costs for an item/items with +CL enhancement on them. Generally costing calculations are an exponential increase (ie: bonus squared x 2k etc., but with the existing items I’m not too sure.

Here is what I have so far, feel free to point out my inevitable mistakes:
Ankh of Ascension (RoF) 60,000gp/4=15,000gp per additional caster level (divine only).

Pray Beads of Karma (DMG3.0) (5000gp+1000gp material)*5(for use per day)= 30000gp /2 (for 1minute/level *since CL12 brings it closest to the 10minute/day stat) brings total to 60000 / 4 = 15000gp per caster level again (no restriction of divine or arcane).

Ioun Stone: Orange Prism (DMG3.5) 30000gp / 2 (unslotted) = 15000gp for caster level (no restriction of divine or arcane).

Here is where it gets a little off kilter however,

Ring of Arcane Might (CArcane) 20000 for +1 CL (arcane only)

Robe of Arcane Might (EH – Eberron) 22000gp for +1 CL (specific school of arcane magic) ***22000gp after the +ac bonus is removed, also the +2ac comes in at 17000gp while all the rest end up at 22000gp***

So any comments on what it would cost to create a custom item with increases in Caster level.

Example:
Ioun Stone: Orange Prism +1 CL = Market 30,000gp
Ioun Stone: Orange Prism +2 CL = Market 60,000gp
Ioun Stone: Orange Prism +3 CL = Market 90,000gp
Ioun Stone: Orange Prism +6 CL = Market 180,000gp
Ioun Stone: Orange Prism +7 CL = Market 210,000gp (x10 because over 200k) so 2,100,000gp

I have done a few searches but was unable to find anything covering this. Mind you I am no googlefu expert.

So does anyone have an official or even just a best fit formula for calculating this?

edit: blocks of text = bad

[TuggyNE]

Generally speaking, most magic item costs scale as the square, not linearly. So an orange prism is 30kgp for unrestricted continuous slotless +1 CL, or 15000 * CL squared; prayer bead of karma in 3.5 is 20kgp for 10 min divine-only +4 CL, or 1250 * CL squared; ankh of ascension is 60kgp for continuous divine-only +4 CL, or 3750 * CL squared (??); I'd figure the orange prism is the closest, so use that formula.

Using 3.0 sources that have been replaced is not kosher.

[muzzilla]

Excellent, thank you

so ioun stone +2, market 120,000gp

iounstone +3, market 2,700,000gp because it hits the 200k limit for non-epic.
and so on.


greatly appreciated!