Coming from an ONM interview with Eiji Aonuma...

"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."


- the shop is run by a Nabbit lookalike
- the shop is a very important place, as it is different from past stores in the games

"Shops in the past Zelda games sold things that would run out once you use them like arrows and bombs, items that needed replenishing. They have never sold an item that doesn't go away after each use like the boomerang or the hookshot."

Link