I graduated from college a few years ago and was debating whether to go for an MArch or MFA. I went to a liberal arts college with an art/pre-architecture major. I eventually decided to go for an MFA (starting fall 2011). Here's some of my thoughts when I was trying to decide - kind of the opposite of your situation but just to put it out there in case it might help...
I love architecture and I have the feeling that I would be able to do it well, and going for an MArch might make my life a bit simpler because I know exactly what I will become afterwards. Even if it might be extremely difficult to find jobs coming out of architecture school (like all other fields in today's economy), there is still a certain path I can kind of follow. On the contrary, an MFA doesn't guarantee me anything. I could be graduated and not only unemployed but also unprepared for any other kind of jobs. Starving, financially unstable, crazy artist. Though, when I decided to go for an MFA anyway, I was thinking that... I don't find myself as passionate about architecture - I love it, but I feel there are so many people who can build just as well, if not better, than I can, while I feel much more at home making art. The combination of MArch and my own personality under this kind of economy and constant social restructuring, I can see myself end up in a big firm doing photoshop, excel and maybe drafting for the already established names, rather than thriving on my own without drastically compromising my ideals. I also wasn't sure if I wanted to physically go through all those intense licensing and examination process that has little to do with creativity. So that's why I decided to go for an MFA, because it suits my lifestyle and aspirations better. Though, if I were more determined in becoming an architect, I would probably stick to the beaten path in today's world - get my MArch, intern in firms, work as an assistant in firms, become a junior architect, become an architect, etc. It might be more difficult to get there if I "take a break" for two years to get an MFA in the middle of this path. But of course, that's just me. Though, if you are pretty sure that you don't want to be an architect at this point, and are more interested in pursuing fine arts rather than architecture, then go for an MFA. I don't think the schools will find it weird that you've already had a master degree. It'll be interesting to combine the practice of both as well, if that's what you are interested too. But if you are pretty determined in becoming an architect, then it's probably not necessary to spend the two years + money + possibly moving to a different location just to get an MFA.
As for the money - there are fully fully funded programs (Ohio State, UMich, U of Iowa, U of Minnesota, Stanford, Cornell, and probably more that I don't know). Good schools like Upenn and Yale seem to offer pretty generous financial aid as well, if you can pay like half of the money. Also, there are high quality programs in Europe too, and they are much cheaper than American schools, even for non-EU students. Look at schools in the UK if you don't speak another language. I was working for an artist in London and she was telling me that when she was young (she's in her 50s), young artists could just move to New York or Paris or London, make art and wait tables, and become famous artists. But she thinks it's so much harder to do this kind of thing now, and many such "opportunities" simply do not present in the same structure. I also thought about using the money for something as a starting fund rather than MFA tuition, but then decided that an MFA might be better for me. Of course, I have friends whose parents are New York-based artists, or some friend's dad is a literature professor at Oxford, or someone's mom is the chief interior designer of so and so big firm, or someone's dad is a philosopher and mom's a poet, and they might not need an MFA to make like-minded friends and be in a creative-friendly environment. I need it because I wouldn't get to a circle of creative people otherwise. Anyways, these are just some personal thoughts and everybody's different so I can't say it'll help you...
