Our MX shop has written the CAME for free (copy of the manufacturer programm plus national/RVSM/MNPS/etc requirements) and supervises us as an CAMO for roughly 5000€/Year. Additional cost is our mx -program (CESCOM - changing to CAMPS soon) - which we had anyway.
Had other offers in the range mentioned... some guys seem to try to make a quick penny ( or in my case, cent) Our Authority is currently drowning in applications - it might get very interesting closer to the deadline...