AA: NYC - Barcelona 1939$ Business Class
In business class nonstop with AA or with 1 stop BA from London to BCN, only a few dates end of November and end of December for that price.
https://www.google.com/flights?hl=en#flt=/m/02_286.BCN.2019-11-28*BCN./m/02_286.2019-12-05;c:USD;e:1;sc:b;sd:1;t:f