Thanks for clearing that up.
But I'm not wild about costing-half-the-item's-cost-to-restore-it thing. I have no problem with this IF the tool/weapon is half used up. (Say it costs $12,000 to repair a $24,000 diamond pickaxe that's half used up.)
However, the way you've worded this is it costs a flat $12,000 to repair the pickaxe- no matter how little or much of it is used up. On one hand, getting a new diamond pickaxe for $12,000 when it's 90% used up (What a bargain! I'll do that all day!)- or getting screwed if it's only 30% used up. That's what I was saying about "play balance".
I think it should be:
Cost To Repair = New Cost X Percentage Used Up.
So, (using our diamond pickaxe as an example), 90% used costs you $21,600 to 'repair' it, 30% used costs you $7,200. To me this seems more 'fair', and it will still let you get a "new" pickaxe for less than the cost of a new one…. what you were after in the first place.
edit: corrected price of diamond pickaxe.