For basketball shots, if its high school level or lower then you should be able to get pretty close to the court. If that is the case then you can more than likely get away with the 50mm f/1.8. This lens runs new for about $120.
I also have used this lens many times for portraits. It is very sharp and the IQ is great. I've also used it on the indoor rides at Disney (though it is a bit on the long side). I've also used it as a general purpose/walk-around/candids lens.
If your using it without a flash, then you have to be pretty much spot on with your focus as using this lens wide open or on the wide open end makes the depth of field very shallow. In other words, don't let the camera choose the focus point. Change the settings so that YOUR choosing what part of your image you want focused.
If your looking for zoom lenses, then that ups your price significantly. The 70-200mm f/2.8's are good if you can't get close to the court or can only be at one spot on the sidelines. This will give you good reach to the other side of the court when the action is away. However, keep in mind these lenses are big and if you can't afford the Nikkor one and have to settle on a 3rd party or older Nikkor with no VR, then you'll want a monopod. These are one of those lenses where the lens, not the camera, is attached to the monopod. If shooting handheld with no VR you'll get a lot of camera shake at the long end, even when pushing the ISO high.
Shorter zooms in the 24-70mm f/2.8 range, even for the 3rd party companies, are almost as expensive as the 70-200mm f/2.8's. I've tried the Sigma 24-70 f/2.8 (@ $600) and was very disappointed with its focus accuracy. I ended up selling it and spending the extra money on the Nikon 24-70mm f/2.8 (luckily I got it before the price went up by a few hundred).
I like the Tamron 17-55mm f/2.8. Excellent IQ and very good focusing. However, its not going to give you much range for basketball. Speed wise it is fine at f/2.8, but it does go for about $500.
I would use my 24-70mm f/2.8 first for indoor basketball. If I didn't have that, my next choice would be my 50mm f/1.8. And I would get as close to the action as possible.
