You have to order a LOT more than $400 to be a wholesale buyer. IIRC, Edmund Davidson had to order a couple thousand pounds of steel to get a wholesale price on his preferred BG-42. A while back a group of us wanted to order a wholesale lot from Hitachi and were told it would be a minimum of 6000 pounds.
Buying a whole sheet is the best way to save money as a small time knifemaker. A sheet ranges from 7X30" to 15X36".
The best thing to do is check with several suppliers and find out what they want for the steel type you need.
Check with Pop's, New Jersey Steel Baron, AKS, Alpha, Niagra, and GFS. Be sure to find out what shipping is as well.
I have found GFS to be very reasonable and has low shipping costs. Just as an example, a 15X36" sheet of 26C3 with VAT and shipping to the USA is a very low price. There are a lot of knives in a full sheet.