I've been collecting mostly german coins and lately have been looking out for the error types. I managed to score this 1889 5 pfennig which, if struck with a low 9, would fetch at least 20 in VF if I remember correctly. Why would this coin with this particular error be well sought after when there are so many reports of other coins and their unique errors?
Another question is about a 1 mark coin I have. I bought 2 from a seller for the same price, and upon closer inspection one of them had a much more pleasing lustre than the other, so much so that I suspect it might be a proof, but I don't think the raised details should be gleaming in the same manner as the lower bits of the coin.