If a buyer thinks it’s not up to snuff, you may end up with less money or no deal.
If you're thinking about changing carriers in hopes of getting a bargain, you may also want to consult our roundup of the best low-cost cell-phone plans for information on how to weigh each offer.
But, beware, if you leave Sprint before that 18 months is up, you'll have to pay the remaining cost of the phone.
Verizon: This carrier offers up to 0 off the cost of an i Phone X for the trade in of an i Phone 7, 7 Plus, 6s, or 6s Plus.
Apple introduced the i Phone X earlier this year, and with it the company announced its first-ever device that sports an organic light-emitting diode (OLED) display.
Those who negotiate the trade-in terms online need to keep in mind that the discounts also hinge on you delivering the old phone in the condition you promised.
So don't say it's in excellent shape when, for example, the screen is cracked.
Rivals like Samsung — which manufactured the i Phone X's OLED panel — have been using the display technology for quite some time, dating back to the first AMOLED display of 2010's original Galaxy S phone.
Display Mate has repeatedly praised the Korean giant's efforts, in fact, crowning its Galaxy S and Galaxy Note lines each time for setting a new bar in smartphone display quality.