Booked myself a LGW-BCN-LGW CE return earlier and used some Avios to bring the price down to £57 + 3914 Avios (after earnings).
Not quite as cheap getting back and you seem to have to have 3? days between the outbound and inbound.
May book myself a £34 Norwegian flight back to LGW or pop up to CPH (shame the cheap Hilton cash+points deal has finished for the CPH Hilton), somewhere else or even jump around a few cities over the weekend.