Posted 05/31/2015 12:52 pm
There was an old discussion thread about interpolating values for grades between those where price points were given; for example EF45, AU55 etc If I remember correctly many people just average them (IE EF45 = (EF40 + AU50)/2) but the argument was that in more cases the graph is more of a curve than linear so a better approximation is taking 1/3 of the difference (IE EF45 = EF40 + (AU50 - EF40)/3). Applying that to Charlton 2015 prices would give you $1,333.33 for an 1861 and $1,250 for an 1864. Just Ballpark of course.
