Usually an amount of currency paid in exchange for a product or service. An implicit or explicit agreement on the used currency is needed for an unambiguous price specification. Sometimes "the price to pay" is meant metaphorically.
In programming context, the price for a change to a program refers to an increased amount of memory consumption, execution duration, latency, worst case behaviour or any other undesirable attribute of the program afterwards.
Note, when handling currency values in a program it is usually the best method to store prices in integer typed variables, counting the smallest denominations. I.e. storing the integer value 323 (implicit euro cents) in an integer is more reliable than storing the floating point value of 3.23 €.
