^^550i is for 11.2k here in pune n 750i for 9.3k.. so under 10k, 750i.. but if u cn extend ur budget, go for 550i... camera n sound both r better than 750i.. but with 750i, u cn firmware upgrade it to w800i.. so the choice is upto to u
also chk this out: *www.gsmarena.com/compare.php3?idPhone2=1840&idPhone1=1090