Sigma 150-500mm F/5-6.3 APO DG OS HSM Autofocus Lens US$725

I'm not familiar with the seller and it is via eBay, but SlickDeals has a link to the Sigma 150-500mm F/5-6.3 APO DG OS HSM Autofocus Lens (Canon or Nikon) for $725 and free shipping. Supposedly it is around $175 lower than advertised anywhere else.

It's listed as new and not refurb with a USA Warranty. That's a great deal I believe. I sold mine used for about $850 back in January.

Think they have been rattled by the Tamron launch