Toranoana has this listed for 1500(actually 1493 for some reason)+taxes so I assumed the price on the site is without taxes.
It depends on the circle I guess. For example the lapis moss one you linked is specified without taxes (price with taxes is 1260
http://d-stage.com/shop/detail.php?seq=19595) while for RGOT-0001 toranoana is selling it for 3314+taxes so the price listed on the page (3480) is the correct shop price with taxes.
This is for shop price, the event price I think is always fine as listed.
Personally I always specify shop price in the entry and event price in the notes (same as we do with non-doujin event releases), but as Efendija pointed out it's not a guideline so it's fine as long as both are specified somewhere.