In Aruba, Blue Delft is usually pretty good price.
Costa Rica, mostly handcrafts. They make some miniture donkey carts, that are very detailed and you can if you look, find them pretty good price also.
Aruba is not really a port of bargains. It is quite a rich island so you won`t see a bunch of hawkers selling junk. Nice prices on jewellry, silver, Dutch made items e.g. cheeses, Delft, liqueurs etc. There is a mall within walking distance of the ship that sells souvenires......jean