I just ordered iphone pro max 128gb online (Tmobile) with iphone 8 plus trade in ($415 credit). The due monthly after promotion is $28.54.
So the total I have to pay for Iphone Pro max 128Gb (retailed $1099):
$415 + 28.54 * 24 months + $99 (down payment) + $112 (tax) = $1310.96
If I buy directly without promotion, the total is $1099 + $112 (tax) = $1211
The difference is $100.
I wonder why there is a $100 difference?
Could anybody help?