Time To Buy A Key Date Rare Coin

I think it really depends on the type of coin. Try finding a proof Morgan, Trade or Seated Liberty dollar in nice condition at a "pretty decent deal". Or, as I recently found out, a 20-cent piece. We're talking THOUSANDS of dollars for each one in proof, compared to hundreds of dollars in a comparable MS grade.

This is hands down one of most informative posts I've discovered on CCF.

Indian Head Proofs are ~$450 in 64 RD. They go to $1100 in 65RD, so I think 64RD is better. I don't like R&B proofs in any grade, I think they can look ugly.

I was trying to think how to answer and it's tough because the criteria from the OP includes something that will be popular years from now. Who really know what will be popular 5, 10, or 20 years from now when the next generation of collectors begins taking over, if they even do. Maybe the rare coin market will go down and a different collectible will be selling for the big money although I don't think so.

So let me try a few basic criteria. Gold and to a lesser extent silver will probably be a better choice. Larger denominations over smaller ones. Higher grade over lower one. If you stick with U.S. coins, and I assuming that is your focus based on the choice of forums, something from the western mints like Carson City or San Francisco (preferably CC) seems to hold it's own due to the wild west connection. 1800's over 1900's.

So I would recommend a silver dollar (Trade, Morgan) or Gold coin dating from the 1800's in MS condition marked CC or S to search for key dates from.

For instance almost all the CC Trade dollars are key dates and then some more than others.

The time to buy a key date is when you see it and have the money to pay for it.