Do you have any coupons ?
你们有优惠卡吗？

Can you give me a discount?
你能给我打个折扣吗？

Today all the jewellery is on sale.
今天所有的珠宝全部折价出售。

Can you offer a quantity discount?
大量采购有折扣吗？

Lower the price and I'll consider it.
你价钱低一点我才会考虑。

I'm sorry. We only sell at fixed price.
很抱歉，我们不还价。

Is there any bargaining on this price?
这个价钱可以商量吗？

We give 10 percent discount for cash.
现金支付的话我们九折优惠。

The best I can do is to give you a discount of 15%.
我最多只能给8.5折。

It you keep bargaining with them, they will reduce the price.
如果你再跟他们讲讲价，他们可能会降一点。