We made a bunch of raisins with some of the grapes we got last week. I would guess it's a couple of pounds worth - sweet and delicious. Now we can eat them over the next several weeks. We were just starting to get sick of eating them fresh so our timing worked out pretty well.
We learned something about dehydrating grapes into raisins though - blanch them for a few seconds before putting them in the dehydrator. It makes the dehydration much quicker by causing tiny fissures in the skins.