Even casting him in the best possible light, as an "knife ignorant" but honest merchant who has had the incredible bad fortune over the past couple years to purchase and resell:
-- A number of "never was" Spydercos which someone assembled from parts. The one which paired a Rescue blade with an Endura handle was a classic.
-- A number of others which appeared to be pieced together.
-- Several Spydercos which could only have "walked" out of the factory as they were never offered for sale.
-- A number of Spydercos with visible seconds notches, with no mention that they were seconds
While there's always some risk buying used knives, those things alone should be enough to make any sensible Spyderco buyer steer clear of his stuff.