[douglas]

5000, eh? Let's see, that puts me 6532 away from level 17. Unless the wings I get as a class feature next level grow overnight (they're completely nonmagical, so that would seem a tad strange), I think it's about time for them to start growing.

Custom magic item discussion regarding Goggles of See Invisibility:
Formula cost is 2*3*2000*1.5 = 18000 gp. A 7th level character is the absolute earliest a PC could afford that by the wealth by level table, and that's if you let him spend almost 95% of his gold on that one item. If you limit secondary items (and this would almost certainly be considered secondary in importance at best by most everyone) to 25% of character wealth maximum, that puts it at 12th level minimum. At that point, a wizard has had the ability to cast See Invis and Glitterdust for 10 levels, and the ability to cast Permanency with See Invis for 3, and the cleric's had Invisibility Purge for 8 levels. Even at that point, such an item is little more than a convenience for a wizard or cleric, certainly not something worth near 25% of his total wealth. Even for other characters, invisibility should not be a major concern at that level, not with almost any competent wizard easily able to neutralize invisibility as a threat. Certainly not anything I would consider worth 25% of a character's wealth. Now, at 15th and 16th level, it's down to 9% and 7% of character wealth, respectively, low enough for me to seriously consider it. Even so, it's still merely a convenience in most situations, as a 15-16th level party shouldn't have significant trouble with invisibility anyway. Around that level it's getting pretty useless for the PC's against a lot of appropriate CR monsters, and in most cases shouldn't be a problem for the PC's either. I don't think giving permanent See Invisibility to the party would make invisibility significantly less of a threat than it already is, outside of really unusual situations.

To sum up, the cost from the formula is prohibitively high for the levels where it would really be useful, and high enough that few characters would consider it until well past the point where the party should have plenty of counters to invisibility anyway.