Upload & Sell: Off
I sold my seven year old 70-200 AFS for $1625, and got the AF 180 for $470.
The lens has a "AF" switch...so you need the lens switch, and the camera body switch in the correct position to get the fastest AF with the 180. (Manual focus switch position engages a damper). It is a screw type AF (one turn for MFD to infinity), and it looks like the D90 takes those type lenses. It seems plenty fast to me, but this isn't based on any objective measure. I have used this lens with the D2X, D300, & D800 Nikon bodies - and it worked fine. DPR claims the D90 has the same AF system as the D300.
A search on "completed listings" on ebay shows the price range for sales (not just listings) are
$379.99, $390.69, $300.00, $355.00, $431.50, $600.00, $450.00, $365.00, $449.00, $381.25, $388.00, $365.00, $360.55 (<45 bids), $324.00, $340.38, $410.00, $499.00, $390.00, and $235.00 (a week before Christmas)
My guessimate would be that a good copy can be had for about $400-$450.