Which f2.8 70/80-200?

On a DX camera.  Amateur use, I have a decent day job and have no intention of going pro.  However, having a decent day job, I'm not shy of spending the right money to get the right product.  Buy cheap, buy twice.

So, which f2.8 zoom?  I know the anti-zoom arguments, but I don't want to be bothered carrying around 2-3 prime lenses when a single zoom plus t/c covers the lot.  Subjects will be racing motorbikes.

The reviews on here seem to suggest that for DX, the Nikon 70-200 VR works out better than the VR2, and both outperform the Sigma offering wide open.  But its about £900 second hand, whereas the Sigma non-OS can be had for less than half that (some as low as £300).  The OS is only a few hundred shy, so I'd sooner get the Nikon one.

Are there any I've missed out?  I had a look at the older Nikon 80-200s, and the push/pull AF ones can be had for less than £300, with the twin ring not so far ahead of that.  The AFS ones tend to come in at about £600 or so, it would appear.

So, assuming you were prepared to pay the £900 for the VR but didn't want to spend more than you would get value for in an amateur situation, which one would you go for?  I am seriously tempted by the VR, but am wondering if it is twice as good as the Sigma non-OS, or whether I would be happy sticking with the Sigma.

Thanks.