So according to Eiji Anouma...
Collecting rupees, the currency of the Zelda world, will be very important in this game. You might think that was the case with all the past games too, but I must say that this time it will be more important than ever and you will need to collect a great deal of them.
Hearing this after seeing that screenshot of the shop with dungeon items in it makes me wonder if maybe you buy items and can tackle the various dungeons in any order or something.