According to my interpretation of my “Le Robert-Micro,” “voire” is a reinforcing adverb used to coordinate ONE assertion or ONE idea by linking it to a single second, usually more drastic assertion (and according to the Office Québécois de la langue français, “voire” is usually preceded by a comma).
For the sake of logic, it would seem (to me, at least) that the two assertions/ideas linked by “voire” cannot be totally mutually exclusive (the French definition/synonym is “ET même” and not “ET/OU même”), and therefore its use in a list of multiple, totally mutually exclusive options (as in your two examples) sounds awkward to me (one can’t be in all three cities at the same time and something can’t be worth all 4 values simultaneously) and I would suggest using “ou même,” as a conjunction without a comma before “ou” (“et même,” par contre would need a comma, but only when it is clearly being used, like “voire,” as a coordinating/reinforcing adverb and not merely as a conjunction followed by “même”).
To use “voire” in a way that doesn’t sound awkward to me in your examples, I would say:
Peut-être est-il dans une ville anglophone, voire à Dublin.
La valeur dépasse 9, voire 14 dans les cas extrêmes !