Buyers are just holding onto their money a tad longer during this period.
Mint standard E46 m3/CS can sell for 25-30k so there will always be that £15k> gap between those and the lowest priced CSL as it's a much better, rarer car with the parts from bmw costing ££££
So much choice on the market at the moment with all the M cars but there is nothing else that gives you that raw special feeling (until you drive it!)
Since owning mine I've already had three random offers on it..but unfortunately it's reserved for my son (when the time is right!)