That's a bit expensive!Could you come down a little?

Could you go down the price a bit?

I found your prices are more expensive than others.

Can you give me 50% off?

I'd buy if it were 20% off.

I think I can get a cheaper one in other places.

I have seen this cheaper somewhere else.

If you reduce this price,I will consider it.

if you cut down that price,I will take it.

Lower the price,and I'll consider it.