Repair cost

Repairs charge a fraction of an item's item value (the crafting-material worth the game assigns it), scaled by how much durability is gone. Pick an item and the calculator reads its value from the same recipe data the craft tools use.

Rule of thumb that falls out of the math: repairing is almost always cheaper than recrafting, but on cheap gear the trip to the station costs more than the bill. The craft calculator prices the recraft side.