Abe sells top notch stuff. Trusted by makers who don’t always sell directly to the public. Def carries a premium but as someone once said to me, he’s like the Cartier of knife retail.
Also, not for nothing, but Abe has a relationship with smiths like Kamon that says any knife of a certain style or over a certain size must go through him. So they get increased notoriety, he gets guaranteed knives coming through his door. So you’re paying a premium to have somewhat better access to those smiths (provided your “add to cart” finger is fast enough)