I bought a 240x30x4mm piece of annealed 01 off eBay last week. It came with some 6mm brass for handle pins and 6mm stainless steel tube for the lanyard tube. There was more than enough of each for one good sized knife.
All in, including postage, it came to £12.65. Other sizes are available from the same seller.
I don't know how this compares to bulk buy prices from the companies mentioned before but for my one-off project it was perfect - just the right starting size, annealed and ready to shape and enough fitting materials.
Hope this helps,
James