Great coin! I got a 10 Mark like yours while working! It was a really hot day, so by 4:00PM I needed a short break from the heat. So I went to cool off in a coin/stamp store. I quickly looked at the gold coins/ noticed a proof 1888-A 10 marks Friedrich III/ also noted the cheap price ($800 Can) for this perfect proof. Lucky for me I had $900 cash in my pocket, he sold it to me for $800 no tax=pretty good deal. The remaining 5 hrs of work went by really fast
In this day of credit cards who would walk around with $900 in their pocket. Except, of course, a numismatist hoping to find deals.