I'll play devil's advocate and say I understand where the overpriced board games come from, though I can't necessarily speak for all games. I've seen what comes in a Frostpunk box and they are massive. Yes it's mostly cardboard but the packing had to be designed for use since you can't just dump everything out. Color printing is expensive but not as expensive as custom plastic minis. Even an injection molded mini first requires someone who can design the mold, then someone who can fabricate it, and now that mold can only make one thing.
Designing has a cost too. Monopoly doesn't need a whole team to write rules. For an RPG like Frostpunk you probably do. You need to design a whole roster of characters, enemies, and encounters, then balance them all.
The reason games like monopoly get away with it is because they know that Hasbro is a giant toy company who can operate on slimer margins and probably get really good deals with companies they always work with. If you're a manufacturer who is asked to make plastic minis for some indie game that got kick-started they are going to charge more because it's a riskier business. They aren't going to be pushing large volume.
The issue with these games are usually scope. They just can't produce these limited run games at a price that more established companies can. But you have to make your board game bigger, with more pieces, and more ways to play because you need to stand out of the crowd.