When having a trade-in I like to negotiate the price difference. You must make an accurate estimate of your trade-in and a fair estimate of the purchase price of the new unit. The difference in price should be your negotiating price.
I don't care how much they give me for my trade-in. Many times the trade-in value is exaggerated to make the buyer think they are getting a good deal. But then the purchase price of the new unit is also increased. All I really care
about is how much money I must pay difference to get the new unit.
To use this method, you must be reasonable about the value of your trade-in and also accurately calculate what the new unit could be purchased outright without a trade-in. Many times people over estimate the true value of their trade-in. This is the critical part in negotiating the price you are willing to pay.
Another important thing to remember no matter what you are buying, do not let the sales person have any ideal how much you really want to purchase the item. If they think you are in love with the item, they will not give you the lowest price.
If I like the deal, I buy; if not I tell them "no hard feelings" and I walk. I wish you the best.
Ray