I am not in the same situation, but please take this advice from an advisor I trusted.
I did not get enough funding to go to my dream school. My advisor suggested, rather then reject it outright, see if I can study part-time for a year, do a really, super job in classes and get recommendations from people in the department to be in a better position to ask for more funding/apply to scholarships the following year.
It did not work in my situation because my dream school did not change their financial aid package after you were admitted, so no luck.
But if we apply it to your situation, it might work out. If you take a few courses (which will cost you say $3000 a course in my world), and rock those courses in the fall term (when recommendations need to be written for next cycle), you might very well have the chance to get great recs, have a community to bounce SOP, and writing samples off of, and be able to hone your research interests based on what you know actually happens in graduate level courses.
If you apply for same school as your certificate, you may be able to transfer the credits, and you essentially paid for one semester, but put yourself in great shape to get admitted and get funding for the rest of your program. Besides, as I am not finishing an MA, I can tell you that if you have 9 credits out of the way before you start, you will love the freedom it gives you to be able to reduce workload, take an elective, and graduate on time.
Good luck, but I think that may be an excellent choice if you can swing the cost of a few courses. In fact, it might put you in better shape than if you were admitted this year, but without great funding.