So I currently have the Nikkor 70-300mm f/4-5.6G AF for use on my D80.
It's okay-ish, but it is really pretty soft above 200mm and the AF focussing is painfully slooooooow sometimes.
Is it worth my while stepping up to the Nikon 70-300mm f4.5-5.6 G AF-S VR IF-ED which is the update of the same lens but with AF-S focussing, VR and low-dispersion glass.
Or should I move to an equivalent Sigma lens (which tend to also offer macro which is not essential, but might be nice).
Or should I just face up to the fact that properly good long lenses are always going to be out of my budget and try to get better with what I've got?

