What economic reason might explain a steep jump in the price of a good or service?

Inflation.

Explanation:

Inflation is a quantitative proportion of the rate at which the normal cost level of a crate of chosen merchandise and enterprises in an economy increments over some time-frame. It is the ascent in the general degree of costs where a unit of money successfully purchases short of what it did in earlier periods. Regularly communicated as a rate, inflation in this way shows a decline in the buying intensity of a country's money. Inflation can be diverged from emptying, which happens when costs rather decrease. As costs rise, a solitary unit of money loses an incentive as it purchases less merchandise and enterprises. This loss of buying power impacts the general average cost for basic items for the normal open which at last prompts a deceleration in financial development. The accord see among financial specialists is that continued inflation happens when a country's cash supply development outpaces monetary development.