In article , acchang@midway.uchicago.edu says...

>I'd like some advice on buying my next lens. Right now, I have
>an 8008s with a 50mm/1.8 Nikon lens. I've found that I shoot alot
>of people photography, so I thought I'd go wideangle. Of course, I'd
>like to get the 20-35/2.8 that Nikon puts out, but I don't have that
>kind of monet to spend. So, lately I've been mulling over getting
>a Nikon prime, or some offbrand wideangles. I've got quite a list, but
>I'd appreciate any help on making my decision.
>Sigma 18-35/3.5-4.5 $390
>Vivitar 19-35/3.5-4.5 $175
>Tokina 20-35/3.5-4.5 $270
>Nikon 24-50/3.3-4.5 $400
>or
>Nikon 28/2.8 D $210
>Nikon 24/2.8 E $330.
>At first, I was thinking I'd just get a prime because
>1) They're Nikkors, much more easily resaleable than the offbrand names.
>2) They're faster.
>3) They'd help me "think" in a certain focal length.
>But now, seeing as how alot of pros seem to be using zooms nowadays,
>notwithstanding the inherent features of framing and saving time with
>zooms, I thought I might try the Vivitar (cheapest of the off-brands.)
>Then, the resale value issues comes back to me, and I think that perhaps
>the 24-50 wuld probably be best. I've changed my mind so many times now,
>I'm not quite sure of my decision. Anyone have any suggestions?
>(or offers too, it's always cheaper to buy used!)

I think you have thought this out, and come to a good conclusion.
I would only add that this professional does not like WA zooms
(the feet are faster/easier than zooming when doing close-in
work [fiddling with the zoom ring slows me down too much],
but for landscapes, a zoom, IF SHARP ENOUGH [most aren't, if you
are critical] would be useful); and, I have yet to see an off-brand
WA zoom that I would consider adequately sharp at the edges/corners,
even well stopped-down - if you care about high-quality image-making,
I would avoid these.
Hope This Helps