Thanee, I don't think you need to multiply the costs based on the original spell's duration if the item's effect isn't fully enduring. If it has charges, logic suggests you should just use the base price, and the multiplication is only there for balancing items that are always on.
Still, that doesn't explain the discrepancy between 205K and 320K. Seeing the math, I favor 205K.
Hmm. And the price for lenses of greater arcane sight would therefore be:
spell level 7 x caster level 13 x 2000 gp x 2 for duration = 364,000?
Now if I had an item with both abilities, you'd multiply the cost of true seeing by 1.5 for 307,500. And together they'd be 671,500.
Or would both effects need to have the same caster level? If that's the case (and if we assume a single wizard 13 is using g.arcane sight [sor/wiz 7] and true seeing [sor/wiz 6], rather than a mystic theurge casting true seeing as a clr 5 spell), then we get:
G.Arcane Sight = 364,000
True Seeing = 6 x 13 x 2000 x 2 + 25,000 = 337,000 x 1.5 = 505,500
Total would be 869,500 gp. Not out of reach for an epic-level character. I wish there was some sort of spell that let you just automatically know the effects of magic items too, though. Even Greater Arcane Sight doesn't do that.
