Depending on where you are located on Long Island, I'd recommend Westbury Nissan or Smithtown Nissan. I bought my truck from Smithtown and they kicked ass. And I've had my truck serviced at Westbury and have gone for many test drives.
Be sure to check out
LINXC (Long Island Nissan Xterras Club) for more info about local dealerships and other people that just bought their Xterras locally.
Dont bother with an aftermarket grille,they cause more damage than not having one, and the stock siderails should be removed if you plan on offroading with the truck.
I drove the 6 speed 05 X, and it was nice. I wish my 01 came with the 6 speed.
I have no idea about MSRP or anything like that locally with the new trucks, so I'm sure someone else can help you out..
Good luck and be sure to check us out on LINXC..
L8r