sullied, if you need more info, let me know, but I think this should cover most of your questions:
1.) Cost is around $1200/credit, so a 4 hour class is going to cost you about $4800. Right now the MGIB is running about $1150 per month assuming that you kicked-in the extra $600. The investment is well worth the $600 b/c you get ~$150/month bump in MGIB benefits (1150 vs. 1000 without the kicker.) I'm going off of Summer 07' rates. The rates change every semester or so, but not by more than 50 bucks or so. Anyway, if you plan it right, you can tap out your MGIB by using accelerated payment and top-up. So, that's about $39k that you WON'T be paying out of pocket. Plus, you'll qualify for T/A at around $4500 a year. Then, if you become a NY resident, you can get NY state T/A that will range from a couple hundred dollars a year to several thousand. I got about 6k from NYS my second year, my wife works, we own our home, and we don't have kids. All of these things will factor greatly into how much assistance you get. Anyway, when it was all said and done, I paid about $12k out of pocket, I have about $30k of loans, and my MGIB is gone! If you have the college fund, your situation is a little different, but not by much.
2.) As far as time investment goes, that all depends on you. A tour at NNPTU is supposed to be 40 months. So, if you wait to start school until after you are finished with initial quals, you should have about 3 years to finish. Since RPI gives you ~37-40 hrs for NFAS/NPS, you still have to take about 90 hours. I finished in 2 years flat, taking anywhere between 3 and 7 classes a semester. Again, this all depends on how motivated you are. I basically worked 10 hr days as LPO at MARF, and then went to class for anywhere between 0 and 4 hrs a day. Some weeks you only go to class for 2 days, others you will be going for 5 days a week. There are some scenarios where you go to work at 11pm, get off of work at 8am, and then go to class from 9am to 1pm. So, you're looking at a 14 hour day if you have to drive to Troy. And that's disregarding homework, study time, and oh yeah, you might want to sleep, too. I guess I sound like a whiney b!t@h, but I don't want you to think it's a walk in the park. The academic part is probably within your ability assuming you aren't an idiot. However, the ability to ignore your friends and family for a couple of years in order to put in the time to do the required work may be outside of your ideal "shore duty."
3.) Times are a changin'. I've heard a nasty rumor that RPI is closing the Malta campus, and that they are requiring guys to go to the Troy campus to attend normal classes. Well, that will be the end of this program. It's just outside the realm of possibility. On top of that, as someone else already insinuated, the command isn't necessarily looking favorably on the guys that go to RPI. Too many of them abuse the system and are screwing it up for guys like you. Example: you now have to maintain >3.20 on cyclic CTP exams to get T/A from the command and to maintain your recommendation to attend class. They won't hesitate to order you to drop-out if you aren't performing at work. Again, this is completely fair and within the ability of most people. However, enough guys come here just to get the RPI degree and try to treat this job as if it is a cush deal at TTF when it isn't, that the command has taken action. The feeling I get is that the command realizes that a large percentage of the people coming here only come to go to RPI and they don't really like it. So, they aren't making it impossible to go, but they are making it harder. If you want to confirm what the campus plans are, talk to Anita Lindemann. She's the navy program coordinator at RPI. You should be able to find her email address in the RPI faculty directory on the RPI website (I think it's lindea@rpi.edu)
4.) Finally, I'll throw you my last little bit of advice (for what it's worth.) I have gotten the feeling again and again that I may have wasted $70k on a degree that is not doing me much good. Why? Because it seems the large majority of the utilities don't care if you have a degree if you are going into op's. SRO's only have to have a H.S. degree or GED. So, if you're qualified EOOW/EWS, you're in good shape without a degree. In fact, Excelon sent a couple of their HR guys here to hold a "career fair" for the Navy guys in the RPI program. They basically said that they did not care what your degree was in, if you weren't qualified EOOW/EWS you weren't going SRO, and your degree only qualified you for an entry level engineer job b/c you don't have any applicable "engineering" experience as far as they are concerned. However, I do know several people that have gone to work at the SAME plant, and the guys that went SRO with EWS experience started at $85k workinig shiftwork, and the guys with the RPI degree started at $85k working a normal day shift job. Take that for what it's worth. I am by no means an expert on the civilian power sector since I am still in the Nav (for 82 more days..........anybody hiring SRO's?

), but I got my degree for my own reasons. One of those reasons is flexibility. I can go op's if I want, and I can go engineering if I want. Having the degree is only going to open doors, not close them. Furthermore, I feel that having the degree makes me a more "acceptable" candidate for management and many other positions OUTSIDE of nuclear power that do require a degree just to get your foot in the door. So, while people here will surely contradict what I am telling you, you should get your degree for your own reasons. In my opinion, the RPI program is GREAT, and you aren't going to find many programs that cater to you the way this one does while providing the level/quality of education that you get at RPI. Just be prepared to pay for it with your wallet and your time.
Again, most of what I have told you is fact. Some of it is opinion. I'm sure you can decide which is which, but if you have any other questions, shoot me a pm and I'll give you my number so we can talk. Good luck, whatever you decide.
-Seth