Artifact costs

[Nelphine]

Except for a windwalker hero. Speed 13 windwalkers are better than 8 greatwyrms.

[Seravy]

Yeah but windwalking is not available in items.
Movement is but that's not what is going to make the item expensive (the best, +2 move, costs only 500) - so windwalking heroes have nothing to do with the item cost. You can already make all 3 items out of 1500 mana crystals - the cost of 3 Wyrms - assuming the hero can even equip 3 items that have movement available as a power.

[Seravy]

   
Here is a list of the current costs and what I think would be a good new cost. This results in an average of 25F cost reduction. Red powers cannot be added to items but appear on a few predefined ones.
Note that powers costing 401 or more had to stay above that barrier otherwise they become available in Enchant Item.
Spell Charges cost that much for each 1 mana cost of the included spell, for example Doom Boltx1 would be 410 instead of 820.

[Nelphine]

I wouldn't decrease the cost of +movement. If anything I'd consider increasing it so that +1 isn't available to enchant item. I'd also consider not changing the cost of armor. Stacking armor is the best way to get heroes to be invincible. Similarly I'd consider leaving anything that grants immunities untouched. (Wraithform being the best example).

In return, you can probably drop most offensive things a little bit more. Heroes are normally dangerous because they never die, not because they kill things fast.

[zitro1987]

Let's see:

New Attack Costs - look pretty good
New Defense Costs - a bit steep for the first 3 points, especially given the highest starting cost for shield/chain. Suggesting 50-130-250
To Hit - Looks pretty good, if a bit low, but I agree with your choice
Movement - Looks good
Resistance - Looks good.
Drastic skill and charge reductions - Looks good, they were way too steep
Spell Resist - Looks good

Some of the low-tier protective or movement-based enchantments still seem a bit expensive compared to their offensive ones. If books are needed to add these spells, it's more cost-efficient to simply cast the spell enchantments.