Olympus E Sieries lenses... expensive!

[ssgv2]

I managed to pick up an Olympus E-500 with 14-45mm lens for £370 second hand. And for a while now i've tried to look for a decent telephoto lens but beacuse the E-500 uses the digital 4/3rds system the lenses are freaking expensive, and i dont have too much money for a new lens (about £270). Are there no cheaper alternatives?