Best wireless keyboard/mouse combo under $100?

I'm trying to get my dad a new wireless keyboard and mouse combo and am looking for something that will last a few years. He seems to go through them every few years and replacing batteries doesn't fix any issues. I don't know what he does to those things!

Anyway, I'm looking at a Logitech MK670 that's about $80. Hopefully it's one of the better ones?