These calculations assume that the buffer has his/her "legendary" weapon, which makes their buffs last for 15 adventures/cast instead of 5.
You have:
Blue Pixel Potion Knob Goblin Seltzer Green Pixel Potion Mountain Stream Soda Dyspepsi-Cola Tiny House Knob Goblin Super-seltzer Phonics Down
You want:
Ghostly Shell Reptilian Fortitude Empathy of the Newt Tenacity of the Snapper Astral Shell Elemental Saucesphere Jalapeno Saucesphere Jabanero Saucesphere Hoojiwat's Hymn Of Healthiness. The Moxious Madrigal Cletus's Canticle Of Celerity Polka of Plenty The Magical Mojomuscular Melody The Power Ballad Of The Arrowsmith Brawnee's Anthem Of Absorption Fat Leon's Phat Loot Lyric The Psalm Of Pointiness Jackasses Symphony Of Destruction Stevedave's Shanty Of Superiority Ode to Booze