From a local camera shop maybe, but you can find it cheaper online. I got it on amazon.com for under 400 bucks back in September. Here's a listing of their offers (used ones look tempting):
[ame="http://www.amazon.com/gp/offer-listing/B00156OZ68/ref=dp_olp_1?ie=UTF8&qid=1233621820&sr=8-2"]Amazon.com: Used and New: Tamron AF 17-50mm F/2.8 XR Di-II LD SP ZL Aspherical (IF) Zoom Lens with Built In Motor for Nikon Digital SLR[/ame]