Brown Sugar Produce also does CSA, where you pay a set price and get veggies throughout the year. Keep in mind, our local veggies are not very exciting through the winter months...things that keep well like cabbages, potatoes, etc. They sell shoots and sprouts too, I think. There are several CSA's (Community Supported Agriculture) available in Brandon - check out
https://csamanitoba.org for listings.
Also if you can find a Hutterite colony around you that sells veggies in season: some grow their gardens organically, but you'd have to ask. Good quality, low prices.
Other than that, I'd say the nicest grocery stores are the Sobey's/Safeway, maybe Co Op. Superstore carries a very wide variety of produce but it's not always "nice".