I purchased a used DVD boxed set from Amazon.co.jp:
it was sold directly from Amazon, though used. I had been visiting the Melmo page every now & then, just waiting to find a seller willing to ship to the USA (at a reasonable price), & nearly overlooked the active [add to cart] button. I guess I was just lucky.
In regard to buying used copies: Though the publisher only profits from the initial sale, nobody else is profiting from selling used copies unless they are rare & thus expensive compared to the price new. The publisher is not deprived of its $, either way. There is no comparison between selling used copies and making available fansubs or raw Japanese episodes online. I read online books provided by PROJECT GUTENBERG (
http://gutenberg.net.au), WHICH STATES THAT THESE TITLES ARE IN
THE PUBLIC DOMAIN in Australia, & people should check the status of those titles in their own countries before downloading them, but that is very different from what you propose to do, Marvelous Melmo.
I love this series; I have added a few of my own comments to the episode guide that I downloaded; noting the appearances of Tezuka's stars; & finding one episode that had a class rep election very similar to that in 1980s Astroboy.
Anyway, there is a ton of nudity in this series, though it is innocent in nature, I doubt any American company would be willing to import it. Note that this was aimed at little children, so the ideas about sexuality & nudity are very different in Japan than in America.