Not that your suggestion is necessarily bad in general, but I don't really think it's necessary when it comes to Factorio. I think it should be clear from playing the demo whether 100+ more hours of that seems worth the asking price for someone. It's probably the most representative demo I've ever played; the full game is just the demo but more. There are no surprises down the line. There are no random pivots to other genres, or the game trying to stick its fingers in too many pies. There's no narrative to screw up. There's no "oh, they clearly just spent all their time polishing the first hour of the game and the rest of it is a technical mess". It's the same gameplay loop from the demo for another 50 hours until you "win".
... and then another 50 hours after that when you decide to optimise things. And then another 100 hours when you decide to make a train-themed base. And then another 700 hours when you discover some of the mods that exist...