Accommodation is going to be your biggest challenge. When you rent in Japan you have to pay the landlord "key money" which is supposed to be like a bond ... except you should never expect to get it back - it's more like a bribe or a favour to get the property in the first place. And accommodation, any sort of accommodation in Japan, is damn expensive. Much more than you'd pay in the US.
However, if you can get that sorted, the good news is that other living expenses can actually be really good value. Food in particular is reasonable and transport, assuming you aren't travelling by Shinkansen all the time, can also be OK.
I don't know where you are living in the States, but even compared to living in NY or SF I reckon Nara would be at least equal. about 8 years ago
Depends on what your looking for.
I've lived in US for 2 decades and Japan is another world as far as culture, space, mentality. etc.
Nara is much smaller than NY, SF like mentioned above, but it's also RICH in tradition/history and you can enjoy SIMPLE lifestyle (not materialistic in big cities)
Also you're close to Kyoto, Osaka and Kobe so I'm sure you'll be delighted in Japan.
Enjoy Japan because I did immensely.
pk from Italy about 8 years ago