This site's own FAQ addresses this directly, listing all three package totals in a single, condensed answer.
Two bottles are $79 each ($158 plus $9.99 shipping), three bottles are $69 each ($207 with free US shipping), and six bottles are $49 each ($294 with free US shipping). Each order is a one-time payment with no subscription.
Worth cross-checking this FAQ figure against the site's own individual pricing cards for consistency, and confirming the exact current price at checkout before you order.