I think I may have first read about Sailor Moon coming to the US in a copy of Toyfare or Wizard magazine. They spoke of a threat to the reign of Barbie. Although hugely popular in Japan from its inception, American audiences warmed up to and cooled down from the paltry selection of Sailor Moon merchandise in the US. The first Sailor Moon merchandise I ever found was some 6 inch "Adventure Dolls" at the old Kmart in Euclid, OH. I can't remember if I bought these or not. Over the years I would buy and later sell a few groupings of Sailor Moon Dolls and other merchandise.
I was really looking forward to ever finding a Luna plush, but signs seemed to point away from that ever happening. In the first few years I would find a few dolls on clearance at different Toys R Us stores. I would buy these as I found them. Then one day in the mall, during a sidewalk sale, Sam Goody/Camelot/FYE or whatever it was called at the time had a plush Luna for like $8 or something. I naturally snagged it up, and felt satisfied. I had originally heard there might be a plush from an article either in Animerica or Protoculture Addicts. These were both excellent Anime magazines for their time. I normally bought the more colorful Animerica whenever there was a Sailor Moon feature, but on one or two occasions I got the more text intensive Protoculture Addicts from Comic Heaven of Willoughby, OH.
In or around the year 2000 there would be two package design changes, one with stark yellow boxes, and one with smooth light blue boxes. I can't remember but these packages represented basically 2 distinct restocks of merchandise. At this point I believe Irwin Toys, now "IT", was handling Sailor Moon distribution in the US. The first few years early in the 00's were probably the best time to be a fan of Sailor Moon if you didn't have access to Japanese imports or anime conventions. Hot Topic ended up carrying a wide selection of Sailor Moon merch, that was questionable at best in its authenticity. Nevertheless, one of the coolest SM items I ever had was a transparent wallet with a Sailor Moon inlay and a nice rugged chain riveted to it. This wallet lasted me a good number of years, probably through the bulk of my early Sailor Moon phase.