Regarding the camera - as others have said a Yashica is probably the best value if you can find a clean working one, but even they have gone up in price significantly since I bought my first one over 10 years ago. You *might* find a decent condition early Rolleicord, but from what I've seen you'd be looking for a long time for one in your price range to show up. Lots of other options out there, like Argoflex, Ricohflex, Ikoflex, Flexaret, Graflex, etc. Seagull and Lubitel are others you might consider. In the end, if all you want to do is get your feet wet with medium format, then the most important thing is to find one in good working condition. If you like shooting with TLRs, you can always upgrade to another model.
As for Japan, a Bachelors degree will get your foot in the door (a TESOL certificate helps a lot too), but you'll probably be limited to conversation schools or middle men organisations like Westgate that don't have the greatest reputation (but they can get you into the university teaching world). If you're lucky, you can find work at businesses, or pick up private students, but I don't think it's as easy now as it once was (nor as well-paying). Some part-time work at universities might be available, but there are so many competing for jobs that a Masters is almost necessary for something decent. If you have a Masters, then the university teaching world is open to you, regardless of your degree (although if its not related to English teaching, then the TESOL certificate will help). When I first came here in 1999 I worked at an eikawa (conversation school) where the base salary was 3 million yen ($35,000 Cdn). It's still about that now - salaries haven't increased much at all in that sector. Despite having a Masters at the time (I now have 2), it wasn't until I got my CELTA certificate that I was offered university teaching work. Most contract teaching jobs at a university will start at about 5 million yen ($58,000), but you have to look at the conditions - I've seen full-time work with Ph.D required go for as low as 4 million a year. Contracts last no longer than 4-5 years, as by law then the university would have to offer you full-time work (thus 2+2 year, or 3+2 year contracts are the norm). There are plenty of teachers who just cobble together various part-time gigs at different universities and probably make somewhere between 5-8 million yen a year, but it takes time to build connections and you'd never get a visa without a contract first somewhere, so you'd have to start with something like that. The best places to be are in Kansai (Kyoto, Osaka, Hyogo) or Tokyo, as there are plenty of universities needing teachers. That said, if you are willing to go to a more rural area (think, the size of Winnipeg or smaller), then there might be fewer options BUT they might be more willing to overlook weak qualifications because not as many people want to live in those places.
