Veer Design Studio have awesome options in the light lehenga section that costs as low as INR 10,000, which I really liked.
This Lehenga Store In Santacruz Has Affordable & Stylish Options
What Makes It Awesome
I saw some really good sister of the bride/groom outfits all under INR 20,000, and even better exclusive bridal wear all under INR 40,000.
Also, they have an online store, here's the link. You can check out their collection before visiting them.