In fact, you can still get 160 tier points for £280 in one trip. Try this for size (booked on Expedia) for London to Valencia via Barcelona:

Sat 11-Jun-2005
London (LGW)
Depart 09:25
Terminal N to Barcelona (BCN)
Arrive 12:30
Terminal B 717 mi
(1154 km)
Duration: 2hr 5min

Flight: 7637
Operated by: BRITISH AIRWAYS -- BA2486
Business Class, Meal, Boeing 737

Barcelona (BCN)
Depart 16:25
Terminal B to Valencia (VLC)
Arrive 17:15 184 mi
(296 km)
Duration: 0hr 50min

Flight: 1344
Business Class, Snack, Airbus A320

Sun 12-Jun-2005

Valencia (VLC)
Depart 14:40 to Barcelona (BCN)
Arrive 15:30
Terminal B 184 mi
(296 km)
Duration: 0hr 50min

Flight: 1341
Business Class, Lunch, MDC MD80

Barcelona (BCN)
Depart 18:00
Terminal B to London (LGW)
Arrive 19:15
Terminal N 717 mi
(1154 km)
Duration: 2hr 15min

Flight: 7642
Operated by: BRITISH AIRWAYS -- BA2489
Business Class, Meal, Boeing 737

Total price: £280.30