FF status does allow extra, for example I get 50kg allowance on QF not 30kg. You don't show any status on your profile, so that benefit is out. You can buy a lounge membership from QF which does give extra 12kg baggage allowance and may cost less than the 12kg excess baggage charge. In general unaccompanied baggage shipping to India is both expensive and takes a long time to clear customs plus some chance of being charged thousands of dollars in duty to release your shipment. Cheaper to pay for accompanied baggage, or just buy what you need upon arrival.