There are a few dynamics to this-
If the coin, even if not slabbed, has high demand among collectors, the price will rise from its initial release price as evidenced on
ebay. Once the coin hits the secondary market, the coins price should grind higher for months, it establishes a track record which helps one avoid a fake out here hype fizzles out quickly and where prices start to drop.
a coin can rise despite an environment where spot prices are dropping. After say a few years, say the coin is a high demand coin among collectors AND spot prices were going higher, for the sake of an example consider this scenario-
1- coin gets released in its first year, mints price was $500. Gold and silver were rising. one year goes by and the coin has a proven track record on
ebay of high secondary prices, coin is going for $800. over the time, there should be a gradual grind higher in price until it stalls out or tops due to various factors.
*another coin gets released in the same series and it ends up having a much lower mintage
* collector cycles
* rising/falling spot PM prices.
There are many factors and each coin is different. However, in my experience, it always comes down to demand. If a coin was popular and well received by collectors, it will rise and hold above its initial release price on the secondary market. Dropping silver and gold prices will impact the coin but the minor drops in spot price dont dramatically impact the coin as collectors that are eyeing that coin jump on it when it becomes available for auction, thus keeping the price up.
However, rising gold and silver do help keep most coins higher.
the only thing that can torpedo all of that is if, in the collecting cycle, that specific coin just loses the interest of collectors, then the demand drops and therefore prices come in.
so it is a hard question to answer and the only way for you to really know what is happening is by being diligent and following, recording prices on
ebay as an example.