My dad always says immediately take 20% off the price and start from there.

He always gives his name and number and within a few days they call. Sometimes he even talks them into a lower price because they made him "wait" for an answer.

I agree with DoesThatSparkle. Act like you know exactly what you're doing and you're in control. You don't have to buy anything; make it work for you.

Also, if you have a trade, don't tell them until you get the price you want. Then you mention you have a trade and make them take that off the discounted price.