I found this blog post about the Oracle 12c OCP exam useful: url
In particular it explained why my Kaplan SelfTest software only covers the new 12c features and not general DBA skills section of the OCP exam.
The Kaplan software I purchased has 50 questions and they are only about new features. The software showed me the gaps in my 12c new features knowledge and gave me practice taking a multiple choice computerized test and I believe the value of these benefits exceed the $99 cost of the software. But, the software surprised me when I discovered that it didn’t cover all the areas that will be on the OCP 12c upgrade exam. The blog post I’ve referenced explains that in the near future Transcender will produce software that includes both sections of the OCP 12c upgrade exam.