As for making peanut butter in a juicer, you may find it's a bit of a chore and takes some patience, but you'll end up with natural peanut butter, that's simply delicious and costs only as much as a jar of peanuts (we were able to get ours for $2.50).
To make the peanut butter, use the mincing nozzle of your juicer (or whatever is recommended by your juicer model.) and run a small handful of peanut butter through your juicer chute at a time. You'll need to run the 'butter' through multiple times as the first few runs will give you a kind of powdery peanut mess. To speed up the process and create a slightly smoother peanut butter feel free to add Peanut Oil to the powdery peanut mix. Continue running the peanut 'butter' through the juicer until you reach your desired consistency - we went at it about 8-10 times.
Enjoy as you would any other peanut butter!