I have not found any material on what access, if any, Google will offer startups and smaller companies to the ITA/Matrix DB (flight, airline schedules and fare data) going forward. Needless to say, this is disappointing on many levels.

Email just received from Google:

Dear QPX Express API Customer,

After careful consideration, we've decided to shut down the QPX Express API as of April 10, 2018.

How this affects you

After April 10th, you will not be able to access the API and will no longer be charged for this service. Until then, you will be charged a reduced rate of $0.02 per query for any queries beyond the 50 free daily quota.

Next steps You don't need to take any action. However, if you are actively using this product you may want to find an alternate solution before April 10, 2018. If you have any questions about these changes, please don't hesitate to contact us at any time.

Sincerely, The QPX Express API team