You can get $40/night (except Fri-Sat) at the Holiday Inn Boardwalk low-rise. For Fri-Sat it's $70. Quality Inn (I think it's on the strip) is a buck a night cheaper.

I haven't heard great things about the Boardwalk, but I think I can safely say there's a much better chance you'll have clean sheets with covers that don't wreak of someone else's sweat, and fewer critters scurrying around your room than at the Vagabond Inn...

These rates are at www.lvtb.com (Las Vegas Travel Bureau) and are wholesale rates. That means that they are not regular hotel reservations, and are more like cheap airline tickets: you pay up front and there are no refunds, changes, or cancellations.