Exam C_ABAPD is now a 3-hour hands-on System Based Assessment (listed as a beta version, 67% pass mark) and includes Joule for developers. Attempts come with an SAP Learning Hub subscription or a single-attempt purchase; SAP does not publish a fixed USD price on the page.
No formal prerequisites are published; anyone can register for the exam.
Does not expire (Tied to release version; newer versions supersede (verify current SAP policy)).
Current SAP developer credential for clean-core ABAP