多少钱 how much
您想要什么 What would you like?
有什么可以帮你的吗? What can I do for you?/Is there anything I can do for you?
如果买者想要某样东西胜过某样东西,应该说I prefer sth. to sth.
eg.我更想要蓝色的胜过红色：I prefer the blue one to the red one.
这是你的找零：Here's your change.
一般接受完服务后都要说一句：Thanks./Thank you.以表谢意.
还有关于“买,卖”的短语：
卖光了：sell out(一般放在句子里用过去式,即sold out) This kind of shoes has sold out.
卖得好,畅销：sell well eg.The books sell very well.卖某样东西给某人：sell sb.sth./sell sth. to sb.
买某样东西给某人：buy sth. for sb. /buy sb. sth.