>>46689629ngl, the vendor puzzle was one of the cleverest thing in Gen I Kanto. It was made so both role player and mechanic player would stumble upon the answer.
Roleplayer is supposed to see the thirsty little girl and try to give her drink from vending machine and after that connect her problem to problem of gatekeeper.
Mechanical player would evaluate the cost-to-effect ratio of drinks and pack their bagpack with them because of how superior they are to everything you can buy in normal shop and sooner or later would come back to check if gates are finally opened.
There's obviously that third group of players that is too dumb to see connection between two NPCs with the same issue and would not bother buying more efficient healing items but oh well, why they even play a jrpg game?