in China--advise on buying jiubing--group order?

Been making rice wine for about 8 months now. I am in China for the summer and wondering if anyone has bought here before. Do I go to the supermarket or is there some other store where to buy them. Have reasonable Chinese skills, spoken and reading, and I noticed online some companies were selling for about 8yuan ($1.25 US) for 500g!! probably wholesale price, but hopefully will be able to get a year's supply (including enough to make winter solstice presents for friends). Please advise.

Thanks,

scott

No experience at all with buying in China. Maybe a supermarket or maybe a street vendor.