But how much it's profitable if we buy for few years? Calculate at least 8% Interesest per year...Forget about possible hike..Bro, there is one hack. Buy recharges as vouchers, which has no limits. I once had 250 or so vouchers (all bought by using Rs50 discount coupons). Another plus point of vouchers is, you can later transfer that to any one. I am looking for buying a dozen Rs1499 vouchers for my family member's future use.