There are currently two (somewhat) prominent EVM certifications:
EVMP: Earned Value Management Professional, issued by the EVMI (The Earned Value Management Institute, the EVM version of the PMI)
EVP: Earned Value Professional, issued by the AACE (Association of Advancement of Cost Engineering)
EVMP costs $3500, but includes a 2 week training course.
EVP costs $500 if you're not an AACE member, and $350 if you are.