This turned out to be more frustrating than i expected :p
play ironworks, gain potion [hand: apprentice, pearl diver; discard: 3 silvers, 1 copper, potion; deck: empty]
play pearl diver, drawing potion, leaving copper on bottom [hand: apprentice, potion, deck: 3 silvers, 1 copper, deck: empty]
play apprentice, trashing potion, drawing 3 silvers, 1 copper [hand: 3 silvers, 1 copper, deck & discard: empty]
play 3 silvers and 1 copper, giving $7, for a total of $8 since ironworks gave $1 from gaining the potion
edit: and dang, I was beaten to it...