Has anyone used Goldstar? I receive monthly e-mails from them and they usually have discounts for advanced purchases of 20-50%. Sometimes BOGO offers. That might be an option. I always use Tix4tonite when I'm in Vegas. However that being said I did buy O and Lance Burton tickets directly.
I always go here to get some good ticket prices. Terry Fator was on sale for awhile but I think it just ended: https://www.travelzoo.com/entertainment/las-vegas/