Of course, they then started selling out of cardboard boxes.
Den of Geek
"What, you think cardboard grows on trees?"
In fact, underproduction was such a problem that it wasn't long before Kenner was accused of deliberately under-producing toys in order to manipulate the market, because holy s**t, malice makes way more sense than Kenner being so completely incompetent.
Nowadays, however, manufacturing is in the hands of Disney and Hasbro (which bought Kenner in the '90s). They know the market, and they know how big the demand is going to be, and not just because they secretly implant microchips into our children when we're not looking. You're simply not going to have the same levels of rarity that make the original toys so valuable. There were shortages on Force Friday ahead of The Force Awakens, sure, but that was a short-term delay -- these guys are playing the long game.
You might have had a shot if there weren't thousands upon thousands of other fans doing the exact same thing. The vast majority of people who bought the original toys didn't buy them to collect -- they bought them to rip open and play with. It's only because of the foresight of a few collectors that we have a collecting industry to oversaturate today. Don't forget, we've already had a taste of this with ... urgh, the prequel trilogy. People bought those toys to collect, kept them mint-in-box, and are now being rewarded with the ignominy of having to sell them for less than they originally paid.