The vacation the Frugal Dude had been talking about since we first starting seeing each other was Mount Rushmore. It took him fifteen years to convince me and now I wished that I had acquiesced sooner. Fabulous does not even start to describe it.  And frugal is the other great thing about traveling to South Dakota. For me sitting at the computer till I get the best price for a hotel room is fun. Some like to sit at the blackjack table in Las Vegas and try to win. The Frugal Diva likes to sit and be assured that she…