The 2-bottle package carries a shipping charge the 3- and 6-bottle packages don't — worth doing the actual math before assuming it's the cheapest way to test the formula.
The 2-bottle package is $79/bottle for a 60-day supply, totaling $158, plus shipping — while the 3-bottle and 6-bottle packages both include free US shipping.
Since this formula's own materials describe best results building around three months, a 60-day supply on the smallest package covers only the earliest phase — worth weighing that timeline alongside the free-shipping value of the larger packages.