Never had buyers remorse, I weigh things carefully before buying. There have been many things I have been disappointing in after getting though, most notably was magic the gathering online, I hated the interface so much that I never ended up utilizing near as much as I thought I was going to.
But I do have instant regrets about saying something in the heat of a moment, or when I mess something up at work. these are things that at least in the embarrassment of the time, I wish I could take back.