Remember Nouse was asking about using a pretty bog standard tablet PC (£100) not a certified EFB solution (£lots).
I wouldn't at all consider trying to jerry rig a non-certified EFB into that role, especially if one were to intend relying upon it. Especially not a used one with an unknown history.
We have one set of jepps on board, and we have a computer and printer available (a luxury, I know, that isn't available in most GA aircraft). We're a three-crew airplane on a standard day. The First Officer generally gets the paper Jepps, and part of his duties are to print out an additional set for the Captain for the departure airport, the destination, and the alternate. That works off Jeppview in a laptop, but it's nothing one would want to rely upon while flying an approach...which is why the paper is there too.
The EFB's that are coming aboard are another matter. I've used them before, but based on my own experiences have a certain distrust. From what I can tell, most of the others to whom I've talked share that distrust. It's only a matter of time until the paper volumes eventually disappear, but I doubt we'll see a time when crews don't print off at least the departure, destination, and alternate before they go fly, as a precaution. Again, based on my own experiences, I'd say it's a prudentone.