Kanga, your 50% rule of thumb may work for you, but it would not work for me. I buy a wide variety of coins. In some cases I would not even pay as much as 50% for a details grade. In others, I would be willing to pay more.
I like $1 modern commemoratives. Next on my list is a 2001 Buffalo. Current retail around $100. But if I saw a PCGS Unc details cleaned, I wouldn't pay more than melt for it. Which is less than 20% of retail.
I also like US classics. I recently bought a 1835
Half Cent. VF-XF. Prior to getting in to coin collecting, I didn't know the US even made
Half Cents. So I'd wanted one for a while. But not so much that I wanted to pay $200+ for a graded AU-MS one. I just like having it around to fill out the type, and show to friends. It doesn't look cleaned. But even if it was I'd be willing to spend 70% to 80% of what an uncleaned one would be. Think of the life of a circulated coin. Especially one that got as much use as a penny. Let's say back in 1840 somebody dropped in in the mud while getting something out of their pocket. And the used their handkerchief to wipe it off before putting it back in their pocket. Maybe they wiped it hard enough to leave hairlines that a
TPG could detect, maybe they didn't. But should that really drop todays value by half?
I also collect a lot of foreign coins. And many foreign collectors do not have the same hangups about cleaned coins that US collectors do. One of my favorite coins in my collection is an 1840 Germany/Prussia 6 Kruezer with what I think is a die break. Sent it to NGC for error attribution. Came back Unc details. Didn't really care. Knowing that many, if not most, foreign coins 100+ years old have been cleaned. So I'd be fine paying 80% to 90% of what I would pay for an uncleaned one.
But back to my original point. It bothers be that NGC didn't put a 60 or a 61 on it. I can't be an expert grader on ever foreign coin I have. Especially since the grading scale many foreign countries use is different. And there isn't anything like the PCGS photograde for foreign coins. In hind sight I wish I had sent it to ANACS. Since they might have put a number grade on it, and I've heard that they are better at attributing errors. But I've also heard they outsource their foreign coins. So I worry that there is a greater chance of things getting lost. I'm tempted to cross it the next time I send something to ANACS.


