Help Buying Tickets for a Vegas Concert

[Nighthawk 1]

So the wife and a few friends are attempting to make it to Vegas to take in Neil Diamonds final show of his tour on Sept 1. They've booked the hotel already but have neglected to get the tickets. So now at this relatively late stage I've began a cursory search for tickets (yikes, hello nosebleeds). Up to this point I've only purchased tickets for local events through ticketmaster. Does anyone have other ideas or websites that are reliable. I'm aware of Stubhub, but have never used them. I don't have much faith in craigslist type ads due to security concerns. A lot of these say that tickets will be shipped by Aug. 28 which means they could be down there (they are going a couple of days early) and the tickets could be in transit---or do these ship by dates mean you will have them in hand well beforehand.