There's no such thing as standard tooling really. There will be some shared components (screws for example, maybe parts of hinges, the metal around a lens known as rimwire) across models but basically any detailing that is different from another model will require another tool to be made.
Plenty of companies use "off the shelf" hinges and rimwire from external suppliers which will be much cheaper as there are no tooling costs but then the look is less distinctive than something that's a unique shape or has a custom pattern.
It's really quite difficult to compare quality directly as there are so many elements to it. One aspect of quality is obviously build quality. A £125 Cubitts frame is very well put together, solidly-built with proper pinned hinges. But it is made with cheaper materials, off the shelf (but high quality) hinges and less detailing than a £600 Jacques Marie Mage frame (although still has custom pins and core wires). Then try to compare those with a £400 Ørgreen frame made in Japan but with very minimalist detailing, or a 20 grand Bentley frame.
Generally anything that's made in Japan will be high quality. Fukui is renowned for its eyewear manufacturing. But even then some Japanese factories now have Chinese subsidiaries where they do some of the work to keep the costs down.
No idea what you paid but pretty sure it won't have been cost price.
The whole fashion industry is essentially a marketing ploy, JMM aren't unique in that. Would you still be as interested in JMM if they flooded the market with product and everyone you knew was wearing them? Also what might seem like a ploy could just be practicality. JMM aren't a big company and it costs a lot to produce frames. Releasing another colour of an existing model doesn't attract any new tooling costs so makes business sense, particularly if the initial batch was in a limited run of colours anyway (factories typically limit brands to 3 or 4 colours per order).