Over the past year I have branched into the following and would recommend them all:
Spartan Games - Firestorm Armada - excellent space fleet game, starter sets are about £30 (10 ships), rule book about £15, and over all you could expand your fleet to a good size for about another £80, so about £130 you have a complete system.
Mantic - Kings of War - fast paced and uncomplicated fantasy rule set - £200 will get you a big army - the models are cheap compared to GW (although some of the ranges are not as accomplished as the GW equivalent, but they, if the issue is price - this will solve it).
Also their '40k' version is out this year - may be worth a look as will be cheap!
Privateer Press - Hordes/Warmachine - not cheap, but cheaper than GW, but a very fun and compelling game with some nice models.
Great thing was, I funded all my new stuff by selling off two 40k armies and all my Warhammer stuff - and still have money to spend on my expanding Magic the Gathering collection - hurrah!
I am the White Knight!