The knifemaker can show a comparable item from his website, CRK can show retail value of their model, and the traders can show their correspondence. If the answer is still no, take it to the next level.
I'm guessing maybe showing proof of actual sales of comparable items would be better than just "asking" prices on a website?
FWIW, it appears clear that 609.4.3 (Nonpayable Claims... Personal time used to make hobby, craft, or similar handmade items...) refers strictly to hobby goods, not goods for sale by a business (whether a custom knifemaker or a car manufacturer). IMHO, being a business would preclude 609.4.3 from even being considered.