Delta, Virgin Atlantic, and KLM have round-trip flights from Dallas (DFW) to Manchester or Edinburgh (MAN, EDI) for $455-$492 with a connection. Flights January to March. Departures on Monday, Tuesday, Wednesday, and Sunday. 7-day minimum stay required.
A Carry-on bag and also a personal item is allowed for free. You can avoid paying for seat selection by accepting the randomly assigned seat at the gate.