It's always interesting to provoce a little bit.
So let's go back to the facts. A Porsche 911 Carrera RS 2.7 (209 hp) from 1973 has a market value around Euro 250 000 (approx $310 000).
I think the Porsche 911 Carrera RS 2.7 could be compared with the 3.0 CSLs. It's from the same epoque, lightweight, more or less the same HPs and has a great race track record. The Porsche 911 Carrera 2.7 RS was, like the 3.0 CSL, also available with different comfort options such as power windows etc (and actually also sunroof).
Looking at the 1973 Porsche 911 Carrera RS 2.7 for sale, in Germany and Europe today, the price range is between Euro 180k - 325k ($225k-400k) with most cars for sale around Euro 250k ($310k):
http://www.mobile.de/home/index.html?lang=en
I don't see any reasons why the BMW 3.0 CSL should not be priced the same, i.e. between Euro 180k-325k.
Top figures for the first 169 carb BMW 3.0 CSLs and the 167 bat ones. Little less for the approx 250-300 produced real light ones (1165 kg) from VIN 2275xxx range, then the city pack 2275xxx ones and then comes the RHD 2285xxx CSL.
The genuine 3.0 CSL Alpina (B2 and B2S) and the race CSLs (VIN 2275981-2276000) plays in another division and could be compared with Carrera RSR and should be valued around Euro 500k-600k ($625k-750k).
The Porsches have already reached this level but there is still a gap for the BMW 3.0 CSL to be filled. I'm pretty sure the Porsche will stay at this level and the CSLs will be moving up in price. It will take some 4-5 years but I think it is realistic. I would not be surprised if during 2010 a street 3.0 CSL would be sold (Auction?) for over Euro 200k.
As always, this is just my humble opinion and the market is always right.
Cheers