Thanks, an interesting link.
So the $22 M1911 Pistol in 1916 would use the GDP for 1916 ($50,717,000,000) and 1971 ($1,164,900,000,000) to get ...
$22 x $1,164,900,000,000 / $50,717,000,000 = $505.31 = Cr 505
and the 2018 M1911 Pistol would cost ...
$1400 x $1,164,900,000,000 / $20,500,600,000,000 = $79.55 = Cr 80
Same issue, only reversed. Now the 1916 gun is more expensive than the 2018 version and neither is close to the Cr 210 'Automatic Pistol' from the rules.
"USE WITH CAUTION" is still the operative word.