Kanji in Context

Hi, I just finished RTK 1, yeah for me, and was considering using Kanji in Context in conjunction with RTK 2 since a lot of people here seem to recommend it. I've found the reference book and workbook 2 in town, but the local book stores say that workbook 1 supplies are out. I tried the Japanese Amazon and there are 2 listed being sold for around 7000 yen, when workbook 2 sells for 1500 yen. Pirates.

Is the book worth it? Know where I can get a copy? Are the workbooks necessary? Any other contextual books worthy of interest?

Thanks in advance.

Should have mentioned that I'm in Kyushu, Japan.