Low-Ball Technique

The Low-Ball Technique is a technique used in sales and other styles of persuasion to offer products or services at a bargain price in order to first attract a buyer, but then adds on additional expenses to make the purchase less of a bargain than originally thought. This is the technique often seen in car sales when the salesperson quotes a low price for the basic car, but then tacks on options, extended warranties, service packages, etc. to end in a much higher price tag than was originally quoted.

This is quite similar to the Foot-in-the-Door Phenomenon.