Gustavo, Thanks for the comments. If you are going to take classes from edX, then edX would let you have access to all course materials and assignments free of charge. You can enroll and complete all these courses and still list this on your resume without paying a dime. I would strongly recommend an MOOC certificate for someone that is interested in transitioning to data science.
My advise is to take as many MOOC courses as possible. Especially those that teach data science using R and Python.
I have written other articles about MOOCs for data science: