Is there a good alternative for Nikkor AFS VR zoom?

My wife has a Nikon D3100, and she wants a zoom lens (70-300mm) for her birthday. From the research I've been doing, the top of the line choice appears to be the Nikkor AFS VR 4.5-5.66 IF-ED. The best price I've seen so far is just under $600.It seems that a lot of people like Sigma lenses for their Nikon SLRs. Does anyone know of a Sigma (or other brand) equivalent for this lens?

While the AF-S VR 70-300 mm zoom is the most robust, you can look at the same focal length lens made by Tamron and Sigma. Just make sure that they have internal auto-tocus and image stabilization.

You can find those lenses on the Tamron and Sigma websites.

The 70-300mm lens is great.
I would not get a third party lens.
A lot of people that do not know about lenses have trouble with them.,
Nikon also has better quality.
If you want to save some money get the Nikon 55-300mm lens.
It is a lot smaller.
It also has the same glass as the Nikon 70-300mm lens.
The 55-300mm lens does have a slower focus in low light.
The slower focus will not be noticeable is most cases.
I would not really care about the slower focus in low light because she will probably not be shooting fast moving things at night.
If she wants the 70-300mm lens get it.

You can get that Nikon AF-S 70-30mmm zoom refurbished for $360.

http://www.adorama.com/...AFVRR.html

Refurbished means it is generally a new lens, but just can't be sold as new. Lenses are refurbished for many reasons, they may be a dealer return, a demo, or a factory re-work that did not originally meet specs. At any rate, they carry a 90 day warranty (vs the 5yr warranty for a new lens).

I have bought several refurbished lenses including this one, and I have never had any issues.

Be careful though - don't buy the Nikon "AF" 70-300mm as it won't autofocus on the D3100 (and it is not really that great of a lens). Make sure the lens says AF-S.

How much do you love your wife?

$119 - Bare 70-300mm? Http://www.bhphotovideo.com/c/product/207359-GREY/Nikon_1928_AF_Zoom_Nikkor_70_300mm.html

$199 - 70-300mm with AF? Http://www.bhphotovideo.com/c/product/549304-REG/Sigma_5A8306_70_300mm_f_4_5_6_APO_DG.html

$259 - 70-300mm with AF and anti-shake? Http://www.bhphotovideo.com/c/product/652371-USA/Sigma_572306_70_300mm_f_4_5_6_DG_OS.html

$587 - 70-300mm with AF, VR and original? - http://www.bhphotovideo.com/...ikkor.html

$5, 800 - 300mm with AF, VR, original, f/2.8, and ED? - http://www.bhphotovideo.com/..._2_8G.html