Well, I ordered one within minutes after watching the presentation, so I guess it's not too expensive for me. That may have been a quick decision, but I don't think it can be characterized as an impulse buy. I saw what it could do, and I recognized that it played to what I needed but couldn't bring off easily with my current set up.
To my mind I wasn't buying a single thing with a fixed and reasonable independent valuation. I was buying an environment in which I could work more quickly and more efficiently with less clutter on my tabletop than is there right now. It feels to me that about half to two-thirds of the money I committed to spending is for the device itself, and the rest buys me the improved work environment and enhanced productivity I anticipate. For that kind of package, three to four K is reasonable.