No - but I bought a book twice on purpose.
I bought a book from one of those stores that doesn't do a server thing and started it.
Then I found myself waiting at the Amtrak station for a really delayed train without my book on my kindle (this was before I started using Dropbox). So I jumped onto Amazon and bought the darn thing again so I could read it. It was a dumb thing to do but I was going to be there for hours and I wanted THAT book. It was also pre-agency pricing days so I didn't lose my retirement fund by buying TWO books.
Now everything I buy goes right to Dropbox and my Kindle so hopefully I'll never have to do something so stupid again.