Rechargeable batteries+charging dock. I just picked up one for about 21$ for AAAs. I use a flashlight and a graphing calculator a lot so I kinda go through batteries.

We'll see how it goes long term, but even if they only lasted two or three uses, they would have more than paid for themselves. I'm confident that they'll keep working a lot longer than that.

These little buck knives are pretty great. They're not exactly masterfully made, but they're a nice size, they hold up really well and you don't feel bad if you lose them or have to sharpen them on a belt sander. And they're made in the US. I don't recommend relying on the clips to retain them though.