What is the typical cost of Summer Course education in the US? I would like to pursue summer college courses - particularly a creative writing class and a computer science class - to help broaden my knowledge and improve upon myself as a person. 

However, looking at some college courses in the local city, tuition alone for a single undergrad course is upward of $800 for a three-credit Summer class.  

This seems a little excessive.  Is this a typical cost for college summer courses in most areas?  And is there a cheaper alternative if I'm seeking to expand my knowledge pool, and not necessarily seeking academic credit hours?
The cost of summer courses in the United States is likely to be as staggeringly variable as the the cost of courses during the semester.  To the best of my knowledge, most universities generally do not change their tuition fees significantly during the summer.

As such, it will range across at least two orders of magnitude depending on the school you are dealing with, and can easily change by nearly an order of magnitude depending on the type of student that you are.  Consider, for example, this table of tuition rates published by the University of Iowa: you will find that summer course charges are almost identical to semester charges, and differ wildly for Iowa residents and students coming from out of state.