lense help

[Jo.T]

hi all,
I have finally got my basic kit where im happy with my focal range but at the moment there are some great prices on lenses with our aus dollar at an all time high.
When i got my 18 - 105mm f 3.5 - 5.6 nikon was leaning towards the Tamron 17 - 50mm f2.8 XR Di II VC LD, at the time i hade a 18-55 & 55 - 200mm i was going to keep the 55 - 200 sold both and went with the nikon 18 - 105mm as the 120 - 400mm sigma was the long zoom on the wish list(now have it). I do have a nikon 50mm f1.8, so im not sure if i should still get the tamron or look at the nikon 180mm f2.8 IF ED for the more low light option.
I do a very broard selection of photography and my current camera is not very good with high iso for poor light(upgrade on the list just waiting to see what nikon release next).

Any sugestions greatly appreciated.

[tokyotom]

"my current camera is not very good with high iso"

This statement makes me feel that you should keep what you have and learn how to use it before getting anything else.