which vending machine is the most profitable?

I was wondering that too. :b

Although there is no definite way to find this out, I find the Ocean Depths Vending machine to be the most profitable because it gives you clothes that easily sell and, in my opinion, the rarity of items seems to be increased. However, Blue Sky also gives books. Which in this hype of Reading Drive expectancy going around, should sell pretty easily and profitably.

thanks :D