At this time we do not support making metadata updates, including price changes, in bulk. However, you are free to update the price of your apps individually.
Please note, when making metadata changes, please make sure to click the green "Submit App" button at the bottom of the page, when finished. Clicking on the "Save" button will only save the recent changes that you have made. You will need to click the "Submit App" button to send your changes to the system for republishing.