Where would you get the cheapest PS3 games? Should you buy off PSN or go and get a BD from a shop?

P.S i live in India where 1$ = 50 Rs. i have relatives elsewhere and i'd say that indians value Rs 10 as much as Americans value 1$ so 60 $ means as much as 250$ to an indian making PS3 games GoDamn expensive. i got the PS3 as a gift.