Earlier today Delta / Virgin Atlantic had a round-trip fare of just $575 from Austin to Manchester, England. This was for a variety of Spring and September dates, with a minimum 7-day stay.
The airlines have been popping these low fares in and out, so it’s worth checking a few times a day to see if this one has returned.
A really fun city close to Manchester is Liverpool, the home of the Beatles. In Liverpool you can take guided tours of locations mentioned in Beatles songs, the homes of John Lennon and Paul McCartney, the faux Cavern Club, the tomb of Eleanor Rigsby, and what is surely the most complete Beatles museum in the world. Definitely worth a visit!