Yes, it feels like a mail-order site to me too.

Not like scam, but more like "hey we are all after you money, and that is about it."

Maybe it is the aggressive adverticing of their products, that makes for that either mail-order/scam/new-age/Evangelical Christian feeling I get?

I'd be much better with a gentler introduction, and then hit harder as I dwelled deeper into the material.

I have actually read a good copy of Sun Tzu already. And after having looked briefly at the sight, I decided to dwell no further into the subject.

I recommend I'Ching translated by Richard Herman, if it has been retranslated into english.