I have never seen any dealer in Las Vegas that has an inventory of suppressors on display. The only place I have ever seen a display case full of suppressors was at the Scottsdale Gun Club in .................. Scottsdale AZ.
RDP has the best idea. Yeah, it takes longer. But it is far cheaper and you don't have to deal with the local dealers attitude. I have purchased three suppressors from Henry at TitleII Firearms of Easley SC. His prices were HUNDREDS less than any local dealer here in Las Vegas. He had the suppresssors in stock, and he is a nice guy to deal with. I then simply had that bought and paid for suppressor transfered to a local dealer and paid the local dealer $50 for the transfer. I had Henry send me an e-mail when he shipped the suppressor. He also gave me all the details so I could print up my own paperwork. After Henry shipped, I waited a couple days and then went to the dealer, had him sign the paperwork and I did everything else.
I found Henry right here on the AR15.com equipment exchange.