I think the question is not whether a provenance is noteworthy or not, but to what degree it is noteworthy. To me, there are different kinds of provenance with different values: 1. The coin comes from a respected dealer or auction house I'll keep the ticket and receipt. It is proof that I acquired the coin legally. In addition, it might convince others further down the line that the coin is authentic. 3. The coin was owned by some kind of famous collector This doesn't necessarily say anything about the coin itself, but it might add further interest. 2. The coin was previously owned by a well-respected numismatist Yes, I'll pay a premium for, let's say, ex BCD coins that come with his tickets. There is little chance that such coins are forgeries. 4. The coin has some kind of pre-1970s provenance For legal reasons outlined by others above, this raises the value of a coin. 5. The coin comes from a noteworthy, published and legally excavated hoard Apart from proving that the coin was acquired legally and is authentic, this might also give fascinating historical context. One coin can have different types of provenance. The denarius below, for example, was bought by me from Kölner Münzkabinett. It was previously owned by the orientalist Fritz Hommel and his son, the classicist Hildebrecht Hommel. The latter also published on ancient coinage. According to the ticket, Fritz Hommel acquired it in 1911. For me, that's good provenance. If it also came from a known hoard, it would be even better. Roman Republic, moneyer: M. Caecilius Metellus, AR denarius, 127 BC, Rome mint. Obv: ROMA; head of Roma, helmeted, r.; before, X. Rev: M·METELLVS·Q·F; Macedonian shield decorated with elephant's head. 18mm, 3.83g. RRC 263/1a.