Oof! I don't know what that converts to in your currency (I see location Japan (I lived in Okinawa for 4 years btw - loved it)) but my last purchase was $75 US for the 1600g powder. Every two weeks would put me at $150 month, $1800 a year.
While I love the product, and use it, I would switch to ESV 2 part probably and add balling part C of theirs or whatever works the best. To lower cost.
Hope all is well but 1600g is the largest container I see. You can always shoot TM a contact request off their web site. They usually reply within 24 hours.