Over 36 years since its intiation the Space Shttle cost us $4.02 billion per year in todays dollars amounting to a total of $145billion by 2005.http://en.wikipedia.org/wiki/Space_Shuttle_program
Over The 16 years of its existence Apollo cost $19,408,134,000 in 2009 dollars thats about $78,616,031,036.99 or $4.9 per year http://spaceflight.nasa.gov/history/apollo/
The difference is simple the shuttle is like a professional photographers camera the Apollo is like an amusement park disposable camera. If they cost the same which do you buy?
Aliens don't come to the Sol System, we're boring and out of the way compared to shorter travel distances between star systems towards the galactic core.