If memory serves correctly I think that some stores such as Lionel and Child World received a bunch of the French carded WGSH figures back in the mid to late Eighties, which is why you see certain ones (such as French carded Spiderman, Batman, Human Torch, etc.) frequently with the price tags from those respective stores on them. I remember many years ago Mark Huckabone talking about how he came across them at a Child World here in Illinois back around that time and bought up a slew of them, which were all on closeout for only a dollar or two a piece. My first carded Spidey that I bought as an "adult collector" was around 1990/1991 from a guy who said he'd bought it just a couple years earlier at Child World.
During those years that these French carded Megos and other stuff like that was being closed out at bargain prices (mid-to-late 80's) I unfortunately wasn't really interested or hunting these things down so I missed out on so many good things. Luckily I was able to grab some of it on the aftermarket not too long afterwards when the prices hadn't totally skyrocketed yet.
Additionally, the occasional carded Spidey and Hulk could be found in the Toys R Us store near me for many years (albeit in very rough shape, cards quite worn out and Hulk often in pieces in his bubble) up until the late 1980s. It also wasn't uncommon to come across the odd Dukes Of Hazzard or Eagle Force toy here and there well into the later '80s. The shelf life of those toys was very different back then from how they're handled nowadays, unfortunately. Though that being said, the Meijer store near me STILL has Star Wars toys on the shelf from three or more years ago that they just cannot sell and refuse to close-out or remove, so I guess some old habits die hard haha.