As often happens on Saturdays for reasons unknown, Allegiant Airlines has reduced fares on many routes to/from Las Vegas. On some routes, fares have gone down $20 or so, but only for travel in July.
A good example is Green Bay, WI to Vegas for $69 each way plus tax. Allegiant sells all its fares as one ways (double for round-trip purchase), and flies all its routes nonstops. It sells fares only on its on web site, and does not list them with Travelocity, Orbitz, or any other fare comparison or fare alert web site. For details, see our Las Vegas page.