Yogyakarta is one of the less expensive city in Indonesia. Things over here are much more cheaper compare with Bali and Jakarta.
Jalan Malaiboro is a main shopping street in Yogya with lot of stalls selling all sorts of touristy things and there is also a mall halfway down the street with a Pizza Hut, McDonalds, KFC and etc.
Street performance at night.
4 days is not enough to explore the whole Yogyakarta. Other than Temples and shopping streets, there are also Museums, Palace and Volcanic mountains to explore. We missed some of these places due to time constrain.