it would be hard to start one nowadays, especially if you're doing it as a "worthwhile investment." The rare comic books that are worth alot now are very hard to find, and usually the only people who own them are the people who got them when they first came out, or the people who payed thousands of dollars for them to add them to their own collection. but if you're doing it just as a hobby, then you could easily get your hands on scans of the rare books instead of the actual things.
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