I got mine and price was 94.90 Euro (strange amount I know).
Andreas was very helpful and BMW Classic are great people to deal with and rigorous with authentication.  They also email a PDF verson so purchaser check all details (Eg name etc) are correct before sending out the original certificate of authenticity. It arrived well packaged and nicely produced. Took a couple of months all up.
However BMW Classic claim that they see some attempts to get certificates for “counterfeits” particularly high end models such as CSLs, so they needed detailed evidence from me - photos of all 3 VINs (ie from plate, firewall, block), registration papers, contract of sale, proof of my ownership and multiple interior, exterior and engine photos.
If you own a particularly valuable high end car such as an original BAT, M1, 507 etc they are likely only willing to certify authenticity of details/VINs based on visual inspection - and they informaed me “all travel needed to inspect is at owners expense” 
Note; they wont supply certificates for non matching cars.