Four tickets to India ain't gonna be cheap.. Even in coach.. Use (or apply for and use) the Chase BA Visa card for the 10% discount. That's worth a lot on four tickets. Keep the flights to all BA metal and you might get decent, segment by segment upgrade options on MMB. Thatll get you into Y+, and from there you can often upgrade into Club World using cash at the airport. This varies by station and flight loads, and there is a good thread on the BA board detailing this.

EXP will also give you free range over seat selection, and since BA are otherwise quite stingy with this, you'll pretty much have your choice of seats.