To add to the price spread and to emphasis the point that the price is ultimately set by the value of the car to the buyer and the desire of the seller to accept that price, and in support of some of the earlier posts on this thread:
An ex Falz Alpina was put up for auction here, in the UK, mid February this year - guide price UKP 200K circa $286K at today's xrate. This is the car campaigned by Peter Werke i the USA until sold via John Starkey into the UK in 2007 - price then $175K and price paid was very close (according to the buyer who was today's seller), that was circa UKP 87.5K mid 2007. The car was completely rebuilt to its original Falz Alpina spec based on photographic records, quality apparently exceptional. I haven't seen it but others have (obviously!) and examples of the rebuilder's work have been featured over here - look up QM Engineering, Brackley, if interested.
John Starkey ad
http://www.johnstarkeycars.com/pages/for_sale/Batmobile.html
February ad
http://auction.simoncharles-auctioneers.co.uk/race_car_auction/BMW_CSL.asp
The period pictures of the car in Falz Alpina colours are the same in each advertisement. NB I believe the VIN in the Starkey ad is a typo and should be 2210270 as per the actual car and all the records accessible on the internet relate to this number.
The hammer went down at UKP 187K and the car was not sold. However, I spoke with the seller very early March and he was negotiating a post auction sale and reasonably confident he would be successful, so let's assume very slightly North of UKP 187K or $267K.
So here we have a CSL (let's assume) sold for Euro 65K late last year (link in the thread) at the then xrate giving circa $91K and UKP 51K, the Group 2 re-creation (link in the thread) sold at UKP 71.5K circa $102K and the Falz Alpina at UKP 187K or $267.
The CSL appears to be very well presented but isn't "original" for a late 1972 build - the wheels (possibly an option?) and the wing set are abvious changes but do they matter? Easily correctable if required by a purist buyer. But the price gap to the Group 2 re-creation is very significantly less than the cost of the work to the Group 2 re-creation car ... by anyone's rates! The price gap from the re-creation car to the Falz Alpina is more significant (!); cost of work is ilkely to have been greater but primarily one is a "genuine" ex racer of the period with supporting provanence and one is a current day recreation with no racing history. I'm not denigrating the re-creation and would love to have it given the funds but its lack of "history" limits its attraction to certain potential buyers. If it's raced in the period series for which it qualifies, and is successful, no doubt its value will increase but it will never compete with one of the ex-racers of the 1970s; this may be an anachronism to some but that's the way it is.
Add in demand versus supply on the day, quality, economic and market conditions, and the desire of the seller to either realise anything reasonable or a minimum target, and we have variations in prices. Whilst I'm interested in those prices it is only for interest's sake, they have little meaning to most of us whatever the age and state of the car as when the time comes to sell or to buy the variable factors relevant at the time will apply. Yes, people will look at recent price history to bracket expectation but the final price will be what it's worth to the parties involved at the time and if there are two or more buyers then the price will be higher.
It keeps many people interested and I'm pleased, and although I'm emotionally attached to my car I can't get emotional about the prices of others.