I picked up a 2wire 1701HG modem/router/WAP this weekend cheap. The power supply was missing. Google indicates the factory power supply is really dodgy. A replacement costs anywhere from $13 to $25, unless you go to your local Gamestop or some other store that sells video games.
It turns out the Sony PSP's AC adapter works fine with the 2wire. I paid $8 for a used one and got it right away of course.
Normally I prefer to get higher amperage when buying replacement power supplies, but the connector is a little weird. The PSP box is readily available, so I'll go with that, at least for a while.
Now I just have to configure the 2wire in such a way that I don't have to redesign my whole home network... That's a project for another day.