As a long time buyer I agree there are ripoff substandard companies, but there are also firms like Lepin (if I got that spelling right) that are higher price and higher quality. They sell kits that Lego doesn't make, like trains, and knockoffs that are unique, like Minecraft style or pirate style working roller coasters. Then there's the old 3d printer, when there are some parts, connectors, etc you just have to have one or two of.

But if I had the capital, I'd be looking into a venture that could make bricks and other nice plastics here in the USA.