Camera eq question for photographers

[markg]

I recently upgraded from Nikon D200 to a Full frame Nikon D700. I am trying to decide what lens i should pick up next. I already have a nikon 50mm f1.8 on the d700 and its very nice. On my D200 I currently use a 18mm-200mm F3.5 F6.3 sigma. This has a really nice range.

My dilema is wether to get the nikon 28mm-300mm f3.5 f5.6 or the sigma 70mm-200mm f2.8 The nikon is about a 1K and the sigma is $1300.

I travel about 4 weeks of the year and take landscape, portrait and some macro photos.