Split snowboards. They were expensive, purchased because it was a "good deal" and they have hardly been used. I also once paid for a class for a lot of money and then never finished it.
I don't count things that were expensive, or for which a large amount of research was not done prior to purchase, or were purchased new for more than used, to be necessarily "un-mustachian" if they were needed or highly desired, and found useful or fully enjoyed. So, for example, the anti-mustachianism of purchasing a new car in some cases would be overcome by needing a vehicle at that point, getting one that was great for the needs it serves, and driving it for a very long time or until it's clearly not useful any more. Things that create buyer's remorse or just become clutter/burdens are in-mustachian IMO because it's ultimately a waste of money. A $50 Kindle that I never use fits that category, while a $900 tablet that I use almost daily does not.
