I make railroad spike knives as well, but would never sell them for ~$80, and would never claim they were high carbon, though I always use HC spikes to make the blades with, and use a superquench or brine solution in order to make them as decent a blade as possible. These are mostly art pieces, and if you're expecting a top notch hand forged blade, you will be disappointed.
Ah just forge weld a piece of 1080 in the edge of your stock and your golden.