The new prices for subscriptions are yet to be revealed. In a statement, Sony said that the price will be "in line with market conditions."
“We are dedicated to bringing PlayStation Plus members the best possible service with the most compelling content. From 1st September 2015 we will be increasing the price of monthly and three month PlayStation Plus subscriptions in line with market conditions. We will continue to invest in PS Plus to ensure an unparalleled experience, featuring the best quality games and features.”
A PlayStation Plus subscription gets PlayStation owners access to the monthly Instant Game Collection, the ability to play online, use the Share Play feature, and access to cloud storage for game saves.
This price increase is limited to the European region as of the time of writing.