Microsoft will be increasing the price of their exams taken or scheduled after July 18, 2016. The price change is happening worldwide and the new price will differ by region. In the United States the price will be increasing from $150 per exam to $165. This $15 increase is less than the last price increase that happened in 2011 with a $25 increase. With the price change differing per region, Microsoft recommends visiting the exam detail page of any exam to see what the new prices will be in your area.
An FAQ post answers many questions such as exams impacted and ways to delay the price increase if you are close to taking one but not before the July 18th change. The booster pack prices are not impacted until the end of August and volume license/academic/voucher prices are not affected as long as the agreements are still valid. Booster packs also provide you with practice tests, retakes, or both.
While a $15 price increase is fairly minor to most, it may make it more important to take advantage of special promotions that Microsoft offers. I recently took advantage of the Windows 8 to Windows 10 free upgrade exam offer and Microsoft is offering another free upgrade for SQL Server 2012 or Windows Server 2012 to their 2016 MCSA version.