...would currency collectors pay a premium for 2014 bills that don't have that marker slash from a counterfeit pen that cashiers use?
Good question. Maybe the marker will fade by then, or maybe that will add to the story way back when we had to mark bills. Pretty soon they will be running a special marker over credit cards.
Everything appreciates in value. Take into account the value of the 1914 USA bills. How much are they worth in varying conditions? I personally have a 1934 $10.00 silver certificate, that someone politely drew in pink highlighter "50" on it. It still retains more than $10.00 in value, so in my opinion the marker is not such a highly destructive force, as compared to people who wad their money up. The only difference between the 1914 and 2014 bills appreciation after 100 years, will be the sheer production numbers. Anything with 100's of millions if not 10's of billions, will be very hard to appreciate in value. Imagine the Japanese invasion currency they swept in the streets, it still is worth very little to this day, years and years later. Only due to the production #