The auction sales amounts for this camera are overstated.
The Westlicht website Staes the following including buyers premium:
Nov 2002 camera 18044 for 7.500 Euro or $8,700 US
Nov 2004 unknown serial number for 4.750 Euro or $5,510 US
May 2007 camera 18044 (again) for 5.520 Euro or $6,403 US
June 2008 camera 18071 passed
Dec 2009 camera 18071 for 6.600 Euro or $7,656 US
(Conversion rate on July 2, 2018)
I have the serial numbers of 12 known 18x24cm Linhof Technika cameras in my database.

Rick,

Shown prices are "with added premiums, converted and inflation-adjusted". So usually they are higher than original sell price.
1) I use EUR to USD conversion on a date of sale, so it fluctuates. Highest Euro in DB I see was 1.57 for USD, lowest 1.05.
2) I always add auction premiums. WestLicht show prices already include them, but for LP Foto it's +20%, Photographica +21%, SAS +18%, etc.
3) Then for sales before 2015 I add inflation adjustment. Otherwise it's hard to correlate sale price to current currency value.

So yeah, you are absolutely correct, sales shown aren't the same as original values.
Eugene.