$50 to set up latest version of Ruby on Rails on my laptop (on campus)

I'm new to using Mac and also new to Rails, having problems getting the latest versions upgraded (PATH errors, write permission errors) and could really use a hand getting it going. I think should be a 30 mins job for someone that is already a Mac and Rails user!

I can meet you somewhere or you can just come to my dorm. Sooner the better as I want to start doing a Tutorial asap!