In an age where food prices are rising in third world, but falling in first world countries, it's incredible (but sadly not unfathomable) that this could be happening. I have to say though, we weren't the only ones to notice this as we did see some other [smart/savvy/shrewd] individuals appearing with luggage bags and trollies coming to see what they could forage.
Being summer there was a veritable plethora of incredible "free" items to choose from. Strawberries & Peaches (both destined for a bin despite their appearance) became jams and purees. Mushrooms became soup and dinner. Blackberries were a welcome addition and added a blackberry blini to our menu. Parsley became a staple herb (albeit for a whole week!) in our kitchens. Tomatoes, under ripe and unwanted were slashed in price, soon becoming a part if our tomato salad and some home made pizza sauce ready to be plucked from the freezer when the time arose.
Basically what I'm saying is that if you are up for a whimsical food shopping trip then definitely consider what may come for free. We've managed to save ourselves some money, but also enhanced what our guests have been able to experience with our menus- something which, of course, is what we're in this for! R.