
My D50 is almost 4 years old the lens i bought it for 850 euro's second hand.
Its a prime lens (300MM AF-S F4 nikkor)and super sharp with a very good bokeh (out of focus softness).
It's aperture is F4 wide open but sharp at there.
I put a kenko 1,4 converter in between (179euro) so i get a still crisp 420mm.
I dont know where u live but i guess u can have a set like this secondhand at maybe 1000-1200 euros.
If u go new with the camera like a D90 u probably going to around 2000 euro's.
This 300MM i have is called the low budget tele because its as sharp as its 2,8 counterpart wich is ofcourse F2,8 wide open means faster shutter times but weights 2000 grams more and about 3400 euro's.
I shot 3 years with a real low budget 70-300 but this 300mm f4 is really worth every cent.