The original price for this book is 1500yen. I've seen this book being sold a couple of times a very long time ago on YahooJapan for what I considered as a good price( around 4000yen at the time ). It is rare, even by YJ standard, I think.
Not to mention the 4000 yen back then had a much stronger exchange rate than today. Compares just a few short yr. ago vs. today, the yen lost 25% of the value. Today, $1 yields 118.016 yen, just a few yr. ago, $1 only yields 88.512 yen.
So back then, you probably paid $45.2, but today if you can get this in Japan for 4000 yen, you only paid $33.9. An item that should worth only $33.9 go to $85, that's unbelievable.
On unrelated matters, we won't see the above exchange rate soon. Supposedly BoJ is raising their rate for the 1st time in yr. this Oct. But as of Fri. Apr 7, the latest news suggest BoJ is raising their rate much sooner. My guess, May-June. Once the 1/4 pt. raise, anyone buy from Japan would definitely paid more, not to mention the int. rate raise will be ongoing.