It is not really a correct place if you expect something extravagant; it's a place selling delicious mash sticky rice, which is a popular snacker in East Asia. Somehow, they make it like a tourist shop for tourists. We local called it Moa-gi, it's made of sticky rice stuffing red bean, peanuts, sesame, and my fave YAM. I am not being exaggerated, with simply a bite, you can taste the freshenss of moa-gi from Tzeng's. My personal favourite is Yam and red bean.
What to buy: Moa-gi is a MUST buy if you come all the way to Hualian. Try your favourite flavour stuffing. Since they add no antiseptic, all of their product cannot last for more than two days, so it's a pity that you cannot take home.
What to pay: Cash is always the best way to pay if you don't want to bear service charge from you credit card company.
Hualien has a large percentage of Aboriginal people, so this area is one of the better places to shop for native crafts.