Questions On Rare Variety Type Coins And Losing Value?

Without knowing what coins and variety you are talking about, I can make some very general assumptions:

1. We really should not assume that the PCGS totals bear any resemblance to the total coin population. To paraphrase Hamlet "There are more coins out there in heaven and earth than are dreamt of by the PCGS grading service". Since you alone found 10 more, it is obvious there could be 1000s more out there in the "wild".
2. Yes, as a general rule, if too many coins of the same kind appear on the market, the price will likely drop. This is fairly elementary supply and demand economics. The demand for varieties of any particular coins is much lower than the general demand for that coin.

We have to know the type of coin, bro. If you don't want to reveal the type b/c you think CCF members are suddenly going to change their collecting habits and rush to snatch up every available example then you are sadly mistaken. Without the info we can't help you. Also I don't know what your budget is but trying to corner the market on a $2,000 coin versus a $200 coin are two different beasts.

It have to be the Seated Type, your icon says it all.

I have an 1829 Bust dime that PCGS states only 25 exists. It's worth the same as the other 1829 varieties. I guess there aren't many collecting those types by variety so YMMV depending on coin and series.

Got it.
In the seated series, eye appeal is more important that rare varieties. I'm assuming you're collection is vf or lower by looking through your posting history.

The reason you're able to find rare varieties is b/c of lack of demand. Small lowgrade coins don't have a lot of demand. Most collectors prefer big coins and that leads to less dedicated small denomination collectors.

I suspect this phenomenon is only exasperated in lower grade coins. If I can buy an r-5 Seated dime in vf for $100 dollars but have another option of buying a r-1 dime with superior eye appeal, why would I buy the rarer coin that is hard on the eyes? Especially if I knew varieties don't effect the price. I would take the r-1 with superior eye appeal over the r-5 anyday.

I wold think the appropriate answer more complex than can be decribed by a "generality," but not in an issue-specific sense. A major factor in deriving an answer is the perception of rarity, and people do not change their perceptions easily, even in the face of hard evidence. If you add (throwing out a number) 20% to the population of a rarity, one would expect a commensurate drop in the premium offered for that rarity, especially when it's being balanced (via your cherrypicking) by an equal drop in the population of the more common variety.

But people don't always change their minds easily. Case in point: There is never a moment in numismatics when you cannot go out and buy a 1909-S VDB Lincoln in any grade you want, except at the very top of the Condition Census. It is the perception of them as a rare and valuable coin which helps to prop their value up. The S-VDB has the second-highest Population in PCGS slabs of any Lincoln, lagging only the 1909 VDB. Their mintage is low, but their availability is not and that data may be found by anyone who cares to look for it

Additionally, some collectors simply will_not change their minds even in the face of new evidence. Yes, your large addition to the population of the rare variety will alter the value, but not everyone is going to get on that bandwagon, so prices (on average) will not fall as proportionally as they should.

Demand is another factor. Lessened rarity will mean fewer non-specialists who seek that coin as a "type" simply for its' rarity. This may affect pricing in a downward direction, or it may not, depending on demand. A more-collected series - like Morgans - can absorb a larger hit than could 3 Cent Nickels, for instance.

If there is a generality, it is in that the closer you get to satisfying the actual collector demand for the coin - not the dealer demand - the faster the price will drop. But I don't feel any hard numbers could be speculated upon.

I don't think you will find a better case study than the Saddle Ridge hoard. Do some research on auction prices before the discovery, during the announcement, and after the sale. It's just one small slice of numismatics of course, but I think that is what you are looking for. Several very expensive pieces lost their status as "finest known" as a result of that hoard.

Numismatic rarities are luxury items, and there are too many factors to consider to give a blanket statement. I could show you half a dozen R3-R5 (less than 100 to unique) ancients that I picked up for peanuts because the market is nonexistent.