Depends on the dates of your trip.
When they first put the London flights on sale it was possible to get Mint for between £950 - £1,000 return ex LON.
I was looking at NYC fares for next January and pricing up as around the £1,300 mark. BA/AA asking for £1,300. Ditto for VS/DL This is for a midweek to midweek so including a Saturday night stay.
Given the similarity in prices personally I’d fly VS or BA purely for the lounge access and the increased number of flights available.
A Monday to a Friday trip is £3.5k. BA and VS want £6.5k