For example, there is an epic-level ring that gives you the ability of a ring of greater energy resistance for all five elements (fire, cold, sonic, acid, electricity). Normally, a ring of energy resistance is 44,000 gp. The DMG states that you adjust the cost by 1.5 when adding additional enchantments to an item already enchanted that takes up a slot (and a ring does indeed take a slot, since you can normally wear just two rings without epic feats), and so you have 44,000 x 66,000(4) for a total of 308,000 (44,000 for the first element, 66,000 for the other four elements). Indeed, there is an epic level ring in the Epic Level Handbook for 308,000 gp that gives you a resistance of 30 to all five. Just as well, I checked the errata, and this cost stands per 3.5 rules (since the Epic Level Handbook was 3.0).
Take a psion venturing to craft the same item. He uses the power Energy Adaptation, which gives you resistances to all energies. This is a 4th level power, and if you manifest it as a 13th level manifester, you get a resistance of 30. So, 4 x 13 x 2,000 = 104,000 gp. This psionic ring does the same thing as the arcane version above, but it has a value of 104,000 gp versus 308,000 gp.
Furthermore, I have a player that wants to craft his weapon with augmented Concussion Blast for 4d6 points of force damage in addition to the damage the weapon deals, and I find his calculations to be horribly low. Unfortunately, I can't find any alternate rules for psionic crafting, which leads me to think either I caught a huge loophole and psionics is that much better for crafting purposes, or I'm completely missing something.
Cross posted to d20games.