Too much. That's a Stern ball which might be why the cost is a bit inflated (Silver is on the new ones). Usually an official NBA game-ball is ~$100.
Once broken in, an NBA game-ball is hands-down the best ball to hoop with, but, and this is an important point, it takes a lot of time to break in a game-ball (weeks of daily use) and it must be done in a pristine setting.
Pristine setting = squeaky clean indoor gym. No exceptions.
The slightest bit of dust/dirt/grime will ruin the leather, especially once it starts loosening up and getting worked in.
But boy oh boy, if you do it right (or are lucky enough to actually have used real game balls), there's no other basketball like it. Silky smooth but incredibly tacky (with a little bit of moisture). The sound it makes on a perfect swish is unmatched. Best of the best, obviously.
That being said, like many others have mentioned, there are better more realistic options out there.