0 the difference between the actual price of an item and the price that a buyer would be willing to pay: --
Buyer's surplus is a measure of the satisfaction you gain from a purchase.
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
Можем да го завършим стъпка по стъпка, колкото и дълъг да е пътят и не може да бъде завършен, колкото и кратък да е пътят, ако дори не маркирате отпечатъка си.