Mana is a Maui destination in itself. You will find everything here, packed into a relatively small building (they even have a kitchen gadgets section that stocks lemon zesters). They carry a large section of beautiful organic and local produce, and they even had my favorite Japanese potatoes (organic and local). Besides their produce, I also bought a couple of prepared lunch items to take on a trip to Upcountry: a vegan hummus wrap and vegan tofu spring rolls. Both were delicious and reasonably priced. This is a must-visit market, especially if you are vegan (their prepared items are clearly marked). I hear their vegan chocolate cake is spectacular.
Cons: Parking in Paia can be tricky, They were out of vegan chocolate cake :(