@ scumbag ... where did you get that £750 fare? Was that just one half of a round trip?
I'e just checked and ba.com is saying
ONE-WAY LHR>JFK £3122 and LCY>JFK £3411.
RETURN LHR>JFK>LHR is showing £1490 [£745 per sector].
One-way trips always cost silly money, and you can't quote the price for half a return ticket - although that could make for a cheaper option [just tear up the return half!!]
Ready to be corrected, of course
Meanwhile, I have read other posts suggesting the WT out, Flat-bed home philosophy; pay for the upgrade on the return flight. Makes for sound economics, especially for those LUCKY people who are expected to work on the day they get back to UK [I had a friend who lived that life all the time, doing the JFK run at least twice a month].