Quote Originally Posted by Cicciograna View Post
EDIT: oh, you meant 70% of the market price... My brain is failing me.
Hmm, so you're saying that those 333 XP paid for crafting the battleaxe do indeed balance the monetary component to achieve the full market price. In fact makes sense. So the price to pay to convert XP to dust should approximately be 12.5gp = 1XP: this way, crafting a new magic item, one would basically pay the full market price of the item, one half in coins, the other half in dust...
That's if you want buying and crafting to have the same price (in other words, you think the customization ability exactly balances the need to spend spells, feats, and time to craft).

Hmm, I'm not sure I like it: I'd like crafting being cheaper than simply buying the item
That's up to you. As long as it's cheaper than buying it on commission (i.e. fully customizable) it's up to you. Just be aware of what the effect will be, and adjust accordingly.