Here in Austin we have a local chain serving grass-fed beef hamburger that's cheaper than McDonald's by $1.19. The 'combo meal' is $0.50 cheaper at McDonald's, however P. Terry's also makes their fries and everything else from scratch, without any robots. I think they try to take good care of their employees as well.
P. Terry's serves "all-natural" beef, but it is not grass-fed. If you want a grass-fed burger in Austin, try Wholly Cow (which is quite a bit more expensive than McDonald's, as you would expect).
http://pterrys.com/menu/