Like Cosmic or others have said, given that tobacco is not a necessity in any stretch of the imagination, it would be hard to make a moral argument against selling old tins at high prices. There is no harm or coercion at play, no laws or reasonable social norms being ignored, nor deception at play. (Also, as an aside, Pipestud's review of Royal Yacht on tobaccoreviews.com convinced me to try the blend, and it has become a favorite of mine, so he's alright in my book.)
But I do want to comment that that something being a necessity isn't the only grounds for whether secondary markets are themselves ethical. If by the creation of a secondary market one were to effectively destroy a man's livelihood through surreptitious means, or to infringe on or to, in effect, steal their property or rights, then one would have valid criticisms as to the ethics of those secondary markets given the observable impacts they have. I think we are so conditioned to take this quasi-libertarian approach to business ethics where are our concerns are largely relegated to mere legality or to yielding to poorly defined "market forces" as somehow being an arbiter of both fairness and morality, that we avoid broader and arguably more important questions of whether a particular business is actually good for the community, and therefore by extension, ourselves.
That all being said, I don't get the impression Pipestud is doing anything crazy at all. Man has some baccy that people are willing to pay top dollar for, and his means of coming about it were honest as far as I can tell. If people want to spend big money on some old Esoterica, by all means. I'm staying on the Yacht.