I did that this Christmas. Missing my wife, I needed to fill the void. I wanted to hear some of my old records (vinyl), especially the Christmas ones so I bought myself a new, higher end turn table. Sometimes we need something to fill the long lonely hours. Usually getting a thing is short lived, but I'm still listening to records and enjoying my sound system. There's nothing wrong with seeking something to make you happy as long as you can afford it.
I practice retail therapy pretty regularly lol. As DogBoy said, as long as you're living within your means and can afford it, there's nothing wrong with treating and spoiling yourself. It's always fun having toys around to play with!