Answer: Low-ball technique
Explanation: The low ball technique is a selling tactics whereby potential customers are drawn to a deal by offering deals at a considerably low initial price. The initial offer is meant to appeal to the customer, get their attention and set their desire on the product to be purchased. After the initial arrangement, then the price is increased, just like in the scenario above, whereby a straight trade-in was initially on the cards, however, this was only to get the buyer to commit to the deal which worked out well before the deal was further increased by an additional $5,000.