It's not just one single manga, there are quite a few that I like and that are not published in the West. Some of them are moderately popular in Japan, but most are obscure. The vast majority are seinen and their serialization has finished.
How do I get these comics published in the West and is it something I can do on my own?
The only ideas I've come up with are with regards to contacting Western and/or Japanese publishers. The former would be just a request of sorts, whereas the latter would involve asking to purchase license, but that pretty much becomes a business on its own and I am not sure if that's what I want. Any other ideas? I am willing to part with a decent amount of resources for every manga, so I am open to any suggestions. The publication medium doesn't matter, both physical and digital are acceptable, though I find the latter a bit more appropriate nowadays.
EDIT: To make it more clear, I am looking for a way to bring some of my favourite manga to the Western audience, not how to purchase manga copies. To illustrate this with an example from the literary world: Suppose I wanted to translate a book from a foreign language to English. It would be perfectly acceptable to approach the author, and/or their publisher, with a sample translation and then potentially negotiate a deal. Or it's not uncommon to directly speak with a publisher who's willing to publish the book and then they do the rest of the negotiation (and legal affairs) on your behalf.