Time is always best spent building a strong base. There is more to pen testing that running a tool and getting shell. I'm not saying that is all you will learn in these classes. They are great classes but they assume you have some basic knowledge going in. What sort of previous IT experience do you have? Are you familiar with the basics of networking? Do you know any type of coding (Python, Perl, etc...)? Do you have a lab you can test in? Also are you going this route because you love puzzles, analyzing data, and taking things apart to figure out how they work? If so you are on the right track. If you are looking to make some big bucks only, then you may not be of the right mind set.
Other than that, you are on the right path by coming here and asking the experts. There are plenty here who are willing to help as long as you are willing to learn. Hopefully one day you will add to this great knowledge base.