More recently, probably a wireless handheld controller for my model railway.
Model railway is a hobby for people with lots of time, space, and money. I generally fall short on two of those, although lately there is a bit more disposable income to go around. Last year I was able to splurge on the control setup that I always wanted, which is a stationary controller - basically you sit at a table and control the trains with two rotary controllers and a touchscreen for a number of other things. Looks a bit like this.
But since it's stationary and my layout is fairly big, sometimes it can be a bit cumbersome to test something that's five metres away. So I decided to also splurge on the matching wireless handheld controller, an Android-based device with another rotary controller and the ability to control almost all aspects of the stationary device.
Did I need it? Hell no. If I had waited a few more months, a perfectly suitable free smartphone app would have been available that I could have used for the purposes intended. But am I loving it? Fuck yes. Irresponsible to boot, but no regrets, not for one second.