Reddit reviews Princess Mononoke [Japan][blu-ray]

The Japanese bluray has both Japanese and English audio, and has the correct, translated subtitles. It's region-free so it works in pretty much any player. It is expensive though, usually hovers around the equivalent of $45-55 USD + shipping. Only other downside of it is that the English audio track is not as high-quality as the Japanese track.

Otherwise, if you're willing to put up with DVD quality, the Miramax DVD release should be cheap to find. Again, it has both Japanese and English audio, and it actually has the correct subtitles AND the dubtitles (I think they're called "English for Hearing Impaired").

This thread might be useful to you; it lists the pros and cons of most blu-ray releases of Ghibli movies.

http://www.amazon.co.jp/%E3%82%82%E3%81%AE%E3%81%AE%E3%81%91%E5%A7%AB-Blu-ray-%E5%AE%AE%E5%B4%8E-%E9%A7%BF/dp/B00EODU3H4/ref=sr_1_3?ie=UTF8&qid=1377063648&sr=8-3&keywords=%28%E3%82%82%E3%81%AE%E3%81%AE%E3%81%91%E5%A7%AB%29

This was posted here a while ago. It says it will be release Dec 4th.

Japanese volumes do tend to come with nicer casing and a lot of extras though, making them really nice for someone who loves the show it comes from. If I'm buying something Ghibli, I'm gonna get one of these sexy little boxes.