your looking at probably anywhere from $20 -$100 depending on the morph. There are ALOT of different morphs. Check this site out

http://ballpythonmorphs.com/

Kings are also cool snakes. There are different kinds and different morphs although not nearly as many as corns.
I have a greybanded kingsnake (alterna phase). He is one cool cat.
check out my photo gallery.

http://www.ball-pythons.net/modules....ndex&cat=10418

I have 3 different morphs of corn snakes and one King snake.