While its been a long time since I've been on an airplane _without_ Wi-Fi, I don't often see power outlets. And as you alluded to, most of the time its $10 for the duration of that flight, whether its 5 hours or 30 minutes.
What airline are YOU flying? I am usually on a 737 built before cell phones were invented. I consider myself lucky if the SkyMall hasn't been stolen, let alone in-flight Wi-Fi.