From June to October each year you will probably find that prices drop radically for whatever produce is ripe at the time. A local farmers' market should not be necessary to enjoy the low price result of massive spikes in supply, but it might help. Each week's shopping brings me delicious, healthy, and inexpensive treats. Last week saw cherries for $2/lb. Blueberries have been $5/qt, sometimes dipping to $4. Strawberries have been $2-2.50/lb. Watermelons are $4-5. A head of romaine is $0.69. Tomatoes, usually quite expensive because they are costly to ship safely, are getting cheaper, and it will soon be the time when people put bags of them out in front of their houses with collection cans for money. Corn on the cob is popular now. I always look forward to September when the orchards give us over a dozen kinds of fresh apples.
Do not be afraid to buy produce that is almost too ripe. My local non-chain market has an area for "seconds", and I have gotten some real bargains. I just bought four acorn squash for $0.50 together, and made a 10-bowl batch of squash soup for $3 (halve and bake the squash for 40 min at 350 F, then peel; add a pint of chicken stock from the last chicken you cooked, a half-pound of cheese (I used colby-jack), two onions, and some spices, then puree in a food processor (adds maybe $0.25-50 amortized depending on how often you use your processor)). I also get piles of tomatoes on their way out, and make fresh salsa (great for chips, chicken, or fish) and gazpacho. When November rolls around, it'll be applesauce time! Also there will be more squash in the fall. Overripe bananas are present all year, and can give you a quick and cheap banana bread. I also got a big bag of discounted but delicious grapes just because they had fallen off their vines.
Cold Winter leaves us with roots, old gourds, a pantry of cans and bags of grains and nuts, but Summer is a wonderful time for a rolling variety of inexpensive and healthy fresh fruit and vegetables. My only food complaint about Summer so far is that the heat ruined the sourdough starter I had out. Sourdough seems to just be my Spring treat.