Google Structured Data Markup has reached that critical point where it is time for it to leave the child age and reach adulthood.
This means that the upcoming version 3 release will pack quite a punch, satisfying the majority of your repeated requests for more integrations, multiple snippets per article, more flexibility with the rating options and more!
I am sure you can understand and appreciate the fact that its initial subscription rate haven't been re-adjusted since the time it came to be even though its features have been multiplied greatly. The users of Google Structured Data Markup are increasing by the day and so do the requests for new features. The increased audience it has ammased is pushing me to increase its subscription rates just slightly to keep its support financially reasonable.
So, from the 1st of August 2017 the subscription rates of Google Structured Data Markup will be re-adjusted by a small yet unspecified amount. With that in mind, it would be absolutely logical if you decided to upgrade your subscriptions before that time and you are welcome to do so but I'm pretty confident that Google Structured Data Markup will keep providing you more and more value by each release.