Atco,
I don't know what sites you frequent, but I have that flight at under £300!
FLIGHT DETAILS
OUT London (LGW) - Tenerife Canary Isl (TFS) 1455 - 21 Apr 2003 1915 - 21 Apr 2003 British Airways 6996 (K class)
IN Tenerife Canary Isl (TFS) - London (LGW) 2120 - 27 Apr 2003 0120 - 28 Apr 2003 British Airways 6999 (M class)
Base Price £ 269.00
Tax £ 22.30
Totals £ 291.30