Late Date Mercury Dime Prices .

With the exception of the 45=P, 42/1 P and D there is nothing remotely rare or even difficult about the late date FB. The 39-S is one of the hardest of them and there's still already several hundred graded and that's really with it not even being worth it below a 66. There's tons of FB late date Mercs out there with a couple exceptions, most just aren't worth grading or selling online so you only see what happens to be local in lower grades.

I'm not sure how we are defining sleeper here, but a sleep should be something whose price is to low for the effort and rarity. There are plenty of examples of this in Seated and Barber coins.

There's nothing sleeperish about common mercs where you have to bank on either silver spiking or 100s of thousands of new collectors wanting to do a set. Common coins will basically always be common. The other fatal flaw is that if the price every does start to climb than the countless FBs that aren't worth grading right now start getting sent in. By all means enjoy the series and collect them if someone wants, but when things are 20-30 bucks for a US classic coin almost a 100 years old it isn't a sleeper.

Ultimately, the prices are based on supply and demand. Demand is not what it used to be. I have gotten several FSB for the years I have, which thus far is only 1942-1945, for inclusion in my mint state sets for those years. The prices did not seem out of line, and in each of those cases, I looked at the coins myself before buying. In the end, I enjoy the coins and don't even think about if they are sleepers or not.