Up-sell 

A method used by your friendly, self-motivated drug-dealer to try and squeeze you for more money.

When your dealer bestows upon you, out of the goodness of his heart, a free bag of better/more expensive product that makes what you usually get from him now seem like a bag of crappy-ass shit. Of course he would deny trying to Up-Sell, but is hoping to turn your usual $100 order into a $200 order, having shown you what you are missing. He might also step up the game by making sure your $100 bag now goes down in quality each time you buy, just enough to be noticed by you but not seem obviously intentional by him.

Up-sell by Luv2rush2 February 28, 2011

up-sell defense 

The act of constantly saying "no" or "no, thank you" or "I don't need that" to sales people who persistently try to up-sell you additional services or add-ons during a point of sale or negotiation of service(s).

So after 10 mins of playing up-sell defense I am totally exhausted. Mind you, I just want a car wash. If I wanted to get up sold and haggled out, I would have gone to the swap meet for some churros and butterfly knifes. How many times to I have to say no, I don't want that super wax?

up-sell defense by leonard b. September 1, 2011

upsell (verb) 

An attempt to persuade a customer to purchase a more expensive item or to purchase additional items so that the total cost will be higher.

Theater staffs have developed the technique of 'upselling,' or convincing patrons to buy larger sizes of popcorn and drinks for a discount

upsell (verb) by Baby Boy April 29, 2005

upsell 

The "art" of tacking on high-priced options to an existing sale under the guise of customer service.

Every time Bill turns on his Sprint phone, it tries to upsell him on their backup service.

upsell by WTFinIL September 29, 2008