I would highly recommend that you see if you can buy a copy of Mark's book vice using another theory, thereby potentially picking up a few bad habits.
Mark will send you a copy of his dictionary if you have a copy of his book and send him an e-mail and ask. Someone sold me a copy of his StenoMaster book a few years back, and it said in the materials that came with it that I would eligible for any updates to the dictionary that were available, so I sent him an e-mail and he sent it to me. Yours should come in .rtf format, so Plover will easily be able to read it. Just remember to disable Plover's built-in dictionary when you add Mark's.
Mark's school uses digitalCAT (http://www.cheapandsleazy.net/cw_dc.html
), so you'll get some exposure to some professional CAT software ... so that's something.
Finally, if you have to save up the money, when you have it all in-hand, stop by your friendly neighborhood credit union, and ask about getting a secured loan. What that is is basically you would put your money into your savings account at the credit union, use it as collateral for the cash or check or whatever they will give you against it to pay for your classes, and make payment as you go through school. When the loan is paid off, you'll have your original money again, to do with as you see fit!