直接杀价： 

That's unreasonable! I'd take it for (100￥.) 这真是卖得太贵了！如果（一百块）我就买。
How about (100￥)? 卖（一百块钱）如何？
I'd buy this if it were cheaper. 再便宜一点我就买。

拐弯抹角地杀： 

Lower the price, and I'll consider it. 价钱低一点我才会考虑。
It's a little overpriced. 这标价有点贵。
I like everything about it except the price. 这东西除了价钱之外我都喜欢。

尔虞我诈地杀：
I've seen this cheaper (in) other places. 我在别家有看过更便宜的。
I heard other stores were having great mark-downs on this item. 听说别家的这个东西在大减价。
If I buy more than one, will you give me a discount? 多买一点有折扣吗？