If you have the time, you can drive down to Boulder Dam, cruise along a section of historic route 66 and visit the south rim of the Grand Canyon. Plan on spending a night at the Canyon so you can see the sunset and sunrise before returning to Las Vegas. Check this page for suggested explorations in the Las Vegas area . The Cost I won't guess at the airfare. That depends on where you are coming from and what season you choose to travel.
Food is available in all price ranges.
This does not include airfare to and from Las Vegas. If you find a package deal that provides all of these features for less money, it may be a good bargain.