This is the 1038th most frequent Japanese word.
値上げ
"値上げ" means "price increase."
値上げ refers to the action or event of raising prices, in this case, the price of gas.
昨年ガスの値上げがありました。
Last year, there was a gas price increase.
値上げ is used to describe the planned increment in prices.
店長が値上げの計画を発表しました。
The store manager announced a plan to increase prices.
値上げ is referring to a sudden and notable increase in prices causing a reaction.