Buying and Selling
The verb for to buy is 买 (mǎi), the verb for to sell sounds very similar: 卖 (mai), the only difference is in the tone. When the two syllables are combined 买卖 (mǎimài) they mean 'business', literally buying and selling'.
To ask for the price of something you can say:
多少钱？ (duōshǎo qián),literally 'more less money'.
or
你怎么卖？ (nǐ zěnme mài), literally 'you how sell'.
The Chinese currency is the 人民币 (rénmínbì) abbreviated RMB.
Its official units are the 元 (yuán, 1 RMB), 角 (jiǎo, 0,1 RMB) and 分 (fēn, 0,01 RMB).
The colloquial equivalents of these units are 块 (kuài) for 1 RMB and 毛 (máo) for 0.1 RMB. Note that the smallest denomination is usually not explicitly mentioned:
十块 '10 RMB'
十块五 '10.5 RMB'
十块零五 '10.05' RMB' (零 means 0.)
十快五毛五 '10.55 RMB'
The cost of something is usually expressed in the following way:
一共 ... (yīgòng) altogether or the quantity followed by the price (or the other way around):
一斤一块 (1 RMB per pound)
五块一公斤 (5 RMB per kilo)
Typical quantities are the 斤 (jīn) 'pound' and 公斤 (gōngjīn) 'kilogram'.
For countable items you can use a numeral followed by the appropriate measue word:
三个苹果一块六 (3 apples cost 1.6 RMB)