The Saturday market is the best way to eat well and cheaply on PEI produce without sitting in a restaurant. Local vendors sell island potatoes, seasonal vegetables, fresh fish, lobster rolls, Island cheese, preserves, and baked goods. It runs Saturday mornings from around 9am to 2pm year-round in a covered building on Belvedere Avenue, a fifteen-minute walk east of downtown.
The market is genuinely local rather than curated for tourists. The farmers who grow the potatoes are often the ones selling them. In summer the fish vendors bring in whatever the catch has been that week. It is a useful way to stock up on provisions if you are self-catering on the island.