Don't have it on me atm, but one of the Faerun books has a pricing for Blindsight (I "think" it was Underdark, in the weapons section, attached to a sword). IIRC, it was almost prohibitively expensive (Update: 30,000 p.68).
Update: Buddy here at work says Arms & Equipment (p. 130) has a "Blindfold of True Blindness" that is 60' Blindsight (but blinds you) for 9,000, which adjusted upwards for sight should give you a baseline.
|
Hmmm. I used See invisibility as the base spell and came up with 18,000 for the item, sans the drawbacks. After figuring in the drawbacks I came up with 9,200gp.
I keep hoping someone has a true line on this type of creation. I also saw the blindfold of blindsight in the MIC for 9000 which gave 30' of blindsight but took normal vision. That used See Invisible as the base spell.
What an interesting question.
Since it was already approached from the other direction - I'll look at the blindsight sword ability.
30k for the ability, but sword and armor effects are typically 2x the cost, so 15K for the base ability in an item spot.
Penalties are "worth" about half a bonus, generally speaking (see SRD Traits), so a -2 to attacks is worth about 1/2 * 2^2 * 1000 = -2K. -2 Search and Spot are about 1/2 * 2^2 * 200 = -400 each.
So 15000 - 2000 - 400 - 400 = 12200 gp.
I'd check the Faerun item, see if it was limited times per day - that seems a bit cheap to me, but not too bad.
I gave out what was effectively a blindfold of blindsight, with some other bonuses, but it was a minor relic.
Could also compare it with Psionic power, Synesthete (trading one sense for another), but that doesn't really seem all that relevant.