Unless you need the Pip Boy to make calls, just get an older android for cheap and use that. Connected to Wifi, it will do everything but make calls, and even then, you can set it up to make calls on the Wifi.
I am in a kind of small town, population 100,000 or so, and there are a couple of stores that buy and sell used phones. That would be the first place to check. I would rather buy a used phone locally than over the internet just in case it does not work. You can check it out in the store before you take it.
You could also use an iPod Touch if you have one lying around or if you can find a cheap second-hand one.