Just to add another view, it could have been a case of buy & sell if it isn't for you.

Some folks jump on almost every blade since the purchase window is so small. Once they get it, if it isn't for them after all they put it on the market.

The big difference is the ones who list half a dozen of a single blade at a serious markup vs a single blade at a little above their landed cost (blade cost + shipping to them + shipping to new owner)