I found quite big Tau and Ultra marine armies on ebay, about to finish, both for around £50.
(a rather large space wolf army from same seller went for 77)
So tempted!
45 firewarriors, one devilfish, 11 battlesuits!! including 6 on sprue, 6 stealth suits, 20 combat drones. for 64 quid including P and P.
3 chaplains, 2 librarians, 7 terminators, 15 assault marines (5 without jetpacks), 25 tactical marines, 3 assault bikes and a dreadnought for £50 including P and P
Bargain.