Lumpy, just so you won't feel like you are ignored................Many ( read MOST) custom makers actually need the knife in the shop in order to correctly design and fit your sheath. That's kind of what defines a custom sheath. Beyond that, I don't know what you spent on the knife, but a good custom sheath depending on the whistles, bells, and add ons you might want will likely cost between $150 on the low side and up to $250 or even more on the high side.
Good Luck!
Paul