OK, I am old and stupid , so please bare with me. I like to purchase pcgs proof "silver" dimes on ebay. Usually pay $6-$8 shipped. I have looked up what pcgs charges and dang if I can figure out how these people can sell a certified , slab, pcgs silver proof dime for that kind of price. Sounds cheap to me. What am I missing?
My guess is they're the result of gambling. That is, they send in 100 of those dimes hoping to get an PR70. You're buying the failures. That is my guess - people trying to hit the lottery.
That's where a lot of them come from. Most of the rest come from people who have no idea how to grade coins, and thinking their coin will grade much higher than it does, but not necessarily a 70, send the coins in to be graded. Only to be sadly disappointed.