Also, I have quite a lot of duplicates from Switzerland 1850 - 1900 that I'm trying to value for sale. Can anybody help me understand why the value of some paper series is higher if its stamped, whereas with other series its higher if it's unstamped.
E.g. number 41 is valued higher if it's unstamped, whereas Scott considers 66 to be valued higher if it's stamped.
Apologies if this is a beginner's question - I am an absolute beginner.