Is it possible to change in-app purchase item's price after it has been published in Google Play? (I'm assuming the app has been published, too).
The whole documentations online at http://developer.android.com as well as http://support.google.com/googleplay/ have nothing about it, only mentioning the possibility of changing price of an app, not the in-app item.
Yes you can change prices at will.
You change the prices on the Developer console not in the application, of course if you have graphics/text in the app that shows prices you need to figure out how to update those, maybe pull them from a server? See: Billing Catalog and Billing Testing
It seems to me that the pricing policy has changed meanwhile. The current docs warn:
Warning: You cannot change the price of an in-app product after you make it available for purchase.
https://developer.android.com/google/play/billing/billing_overview
Any recent experience on this?
Yes, you can change prices of managed and unmanaged in-app products, but NOT for subscriptions. This is because users will always see the latest price of products as they purchase them, so changing the price of a managed/unmanaged product is fine. However, customers who have already purchased a subscription and agreed to a certain price per month (or per year) cannot be made to pay a different price without knowing it.
来源：https://stackoverflow.com/questions/10297238/change-the-price-of-in-app-purchase-item-after-publishing-android