Generally you look for the least expensive that meets your other criteria (grade, mintmark, etc.).
With the proviso that some series have very few key dates and non-key dates don't always get slabbed. If you go out to NGC or PCGS sites they have population reports that will show you what might be available.
For example:

If you want an MS65 or MS66, there are a lot of 1964 dimes.
With the proviso that some series have very few key dates and non-key dates don't always get slabbed. If you go out to NGC or PCGS sites they have population reports that will show you what might be available.
For example:

If you want an MS65 or MS66, there are a lot of 1964 dimes.
-----Burton
Author: 3rd Edition of the Sample Slabs book, https://www.sampleslabs.info/
50+ year / Life / Emeritus ANA member (joined 12/1/1973)
Life member: Numismatics International, CONECA
Member: TNA, FtWCC, NETCC, EveryCountry (online) coin club
Owned by three cats and a wife of 40+ years (joined 1983)
Author: 3rd Edition of the Sample Slabs book, https://www.sampleslabs.info/


















