There are artists willing to do art / animation for free, cheap, credit or royalties, if you look for them.
Can always put a request out on indiedb or in some of the game dev groups on facebook or reddit, etc.
http://www.reddit.com/r/gamedevclassifiedshttp://www.indiedb.com/jobsAlternatively if you don't mind your character only doing sideways walk animations (mostly) then you could use sprite parts & a program like spine, spriter or anime studio pro for creating 2D skeletal / bone animations.