You can request that Google Extend your 50,000 quota. Note: I am not sure if they charge for this or not. You can only do this though the old Apis console for your app. I have been unable to find this feature in the new cloud developers console. (I have sent in a feature request on it)
On the right you will find a link to Request more. But you need to make sure that you don't have to many errors returning from the API this will effect weather or not they will except your request to extend.