Short answer
Buy from Surat for synthetic sarees, lehengas, and polyester/viscose fabrics at factory prices; buy from Ahmedabad for cotton fabrics, readymade kurtis, and denim jeans; and buy from Mumbai for boutique designer fabrics, western wear, hosiery, and export surplus.
All three cities sit on the same Mumbai–Surat–Ahmedabad rail and highway corridor (connected by Vande Bharat Express in 2 to 5 hours), and each leads in a different segment:
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