The salesman has tried to influence you via the That-not all technique .
Explanation:
The "That's Not All" technique is being used by marketers to Convincing potential clients, who are reluctant to buy a product. A demand is required and another argument is stressed before an individual is asked to comply with the request.
So you can, for example:
The increments can be specific but each individual can surprise and delight. This can also benefit if the final increase is particularly desirable.