Apparently this is somewhat common practice among some -- for a number of things, not just knives? The reason I ask is that a friend has this truly beautifully made knife. I asked him what it was for, as I wasn't sure how to hold it? He laughed and explained the online shopping in the middle of the night phenomenon to me.
LOL! Not knives, guns! A few years ago, I self imposed a 10pm curfew on browsing GunBroker for that reason. I can’t remember which firearm I ended up with, but I was surprised the next morning to learn that I’d won. I don’t even remember bidding.