Wow. I went to the fish market in Maputo last week to get some lunch and got a really nice over all experience. I can not enough recommend this place! The fish market is located near the beach in Maputo so you get a nice walk first to get there. Then, when you enter the place, you see fish everywhere and in all different shapes. Prices (without trying to bargain) was 2 euro for 1 kg of clams, 2 euro for 1 kilo of crab, and 2 euro for ½ kilo of tiger fish. All the fish is incredibly fresh and some is still alive, like the clams and the crabs.
After selecting what you want to eat you can, instead of taking it home, go to one of the nearby restaurants and ask them to cook this. The price for this is about 2 euro per dish, and if you want rice or salad to the dishes it will cost you extra. I can truly say this was one of the best food I have eaten in my life, specially the fresh crab. Because I love sea food I will really miss this place when I move away from Mozambique.
A tip is to go into the kitchen when they cook your food, both because it is interesting and also to see that they actually cook the food you brought and not some older fish to save money.