You only refer to the CAD models. Making a complete new set of plastic injection mould tools of the different size would run to hundreds of thousands of dollars. I am a toolmaker..
I don't mind Gan or whoever making a healthy profit if they deliver. We need to provide the incentive. Otherwise we will just get all the same products, complacency and probably very slow progress. Look at the original Rubik design. That did not change much for a very long time. Innovation, risk taking, experimentation, long-term development and attention to details and quality all involve costs.
I'm actually excited at this Gan mini Pro grade cube and am glad someone bothered to make such a flagship cube in a small size, though there's a risk in recovering costs if sales projections are not met.
Except for one reviewer's caution about the quality of the spring adjustment system, everything looks very nice IMO, based on the specs and on other early positive reviews in China. I am confident it will do well, since it's not a smartcube (and Gan really needs to repair it's reputation there).
It's a bold step, but not unreasonable given all those very young but great speedcubers, who had to until recently struggle with 56mm cubes, or settle for second tier cubes. I'm not surprised that with this release, there will be more young cubers rising to the top. 53mm, 54g, plus top design, specs and quality, improving even on the 11M Pro that it is based on, at a lower price. What's not to like?
It's good to have choices.
Dan