OK, I know I'm biased because I own the note in the previous post, BUT something is bugging me...
The back-of-the-book section of the Charlton catalogue contains special serial numbers and error notes together. Consequently, people treat the pricing in these areas the same, meaning they use the same percentages to calculate values of circulated notes. Clearly, the pricing schedule for special serial numbers does NOT apply to error notes because errors are errors regardless of grade.
Just look at the example for 1870 Inverted design shinplasters (E27)... The note shown in the previous post is valued at $2,500 for the error. But an 1870 series B shinplaster in Unc is currently priced at $3,250. WHAT THE HECK?? The error note is worth LESS than the non-error in Unc?? Because of discrepancies like this, I have to regard the error price as a premium. Add the two numbers together ($3,250 + $2,500) and you get the REALISTIC price expectation for a rare old error note in Unc.