The words "Cheap", "Free" and "Mac" shouldn't be used together...
I don't know, I run a lot of FOSS software on my Mac no issues. While it wasn't cheap, it wasn't all that more expensive than a similarly loaded laptop from another manufacturer. I used to hate on them pretty hard till my past two jobs both issued me one for dev work. After seeing the value first hand, using it, and beating on it, it finally made sense. Home-brew is your friend.
It's why the most recent purchase went that way. Never in a million years would I have thought to switch till my employers dropped them in my lap. Note I do embedded dev work, not iOS work. I've discovered a lot of my dev and IT friends are making the switch.
As to the main thread. I run bootcamp for other reasons so I also just spool Phoenix in there. Phoenix runs decently well in VMware too BTW, I suspect Parallels has decent performance as well. Neither options fall into the Free camp, but definitely in the well supported camp.