Nikon 70-200mm f2.8 lens alternative?

I'm looking for a cheaper alternative to the Nikon 70-200mm f2.8 lens.
I don't have the money for the name brand.
I have seen the Tamron 70-200 and the sigma 70-200.
My pricerange is $0-$600, are there any other lenses that i can get new or used that provide the 70-200mm range and the fast aperture?

Added (1). Yes, I have a D7000 so the non AF-s thing is fine.
But does the Tamron 70-200 have a built in motor or is it a screw drive?

Mmm go to youtubes channel thatnikonguy he has tested all three

The Tamron came out pretty well.bit slow focus and for some situations that might be a killer. But for many users it is capable enough. And well. The image quality is great!

Sigma kinda the same but check his youtube review of those.

If you use the long end of the zoom range more than wide, Its getting on a bit now but the 180mm f2.8 AF could be a good used buy, within budget. It is a very high quality prime lens.

OK, it is not AF-s, and that will be a problem unless you have a D7000 or upwards, but it is the closest I know.