When I started selling stuff to pay for my "new" camera, I found out it's not too hard. I said "the next extra hundred dollars I have, I'm going to get myself one of these!"
That was a year and change, and lots of groceries, eating-outs, and various bills later. I went through a few thousand dollars and didn't get my lens. Then a couple of weeks ago, I found an eBay seller with a pile of these refurbished by Nikon for just under $100 each. My Darling Wife said "You really want it. Just get it."
...I did. Thanks Jesus, I love it. As BR said, "That's really, really fast!" Indeed. But the speed is only half the reason it's great. The other half is that it meters exposure and autofocuses on my camera (unlike my red-headed stepchild lens). The other, other half is that it's pretty sharp without trying hard at all. Click the camera-shy dog to enlarge, then right-click and View Image, and hit the Plus magnifying glass.
If you have a Nikon without a focusing motor in the body, or if you just gotta have instant manual focus override without turning a switch, get one of these instead, for an extra $100.