If you want to shop for clothes, I'd rather recommend to visit the market in Quatres Bornes (you can get there by bus from PL, it's not very far).
Lots of clothes, very cheap prices. But be aware that the "brands" are not real!
In PL I remember a big food-market (tropical fruit, meat) - also nice to visit. As for shopping, I did find the so called "designer fashion outlets" to be quite pricy. About the same price I would pay for it here in Germany.