I found this great constant aperture manual zoom lens on eBay for a very good price. It has some specks of dust in the lens so that prevented a lot of people from bidding on it I guess. It was a bit of a gamble but I really like the lens. And, the few specks of dust do not influence picture quality.
I use it now instead of my Nikon AF-s 18-135mm lens which I don’t like that much because of vignetting and the cheap plastic lens mount which sometimes makes bad connection with the camera body.
This lens is completely different though. It’s all metal, built like a tank. It’s a bit faster at f3.5 and I like the bokeh. Downside is that this lens in combination with the D300 body is on the heavy side.
What I really enjoy is the manual focusing. It may sound strange but I think it gives me more control over my images although I have to work a bit harder to get the pictures I want.