i tried kolkata, i tried mumbai i tried purchasing from users and i have come to understand all above sources are disappointing compared to the excellent experience i have had from ebay.com. primarily from UK/Japanese based sellers.
advantages:
1. you could buy music you want
2. grading systems are pretty accurate
3. it's much much cheaper than buying locally. i have mint condition beatles japanese LP's with Obi for 1100, ECM label Pat Metheny records for 600 and one of the best deals ever, 16 elton john lp's in mint condition for some 2200 (only in this case i had it shipped ot a freind in US, 16 lps weigh quite a lot.
all said, shipping to india is safe as they pack beautifully. and incase you get lucky with LP Lots then it would be advised ot ship to a freind in US/UK.