Ashmon is a perfect place if you are looking to buy cotton suit-sets, ethnic dresses, skirts, kurtis. You won't find a lot of stuff here that has embroidery or heavy work on the garments (and that is what you do not need in summers) but you'll be spoilt for choices when it comes to selecting your favourite print (because they have got tons of them). So, good luck!
The price range for cotton suit-sets start from INR 700.