Neat! Offers like your produce box are rare up here since there's very little in terms of local produce other than potatoes and occasionally apples in the summer. Anything heading here on a truck is usually destined for a store in my city.
I have had some luck with Walmart deals. They used to throw out the remaining produce when they went to restock, but lately they've started bagging it up and selling it for $1 per bag. Most of it's perfectly fine, although you run across the occasional bad apple (Pun intended). Just today I got three cucumbers, four avocados, and about fifteen bananas for $3 total. Normally this would have run between $10 and $15.
I'll try to remember to tag you when we try the challenge. My girlfriend previously talked about this sort of thing and seemed pretty interested in giving it a shot.
PS - I was in Bisbee a few years ago on vacation. We flew into Tucson and took a car from there. The desert was an awesome change of scene from our Canadian winters, and the heat was a welcome break :) Nice area you live in.