Overpriced compared to the 12..certainly. The Mini, with the smaller screen, is also in that line-up a niche product. Peoples willingness to spend money on the regular 12 and 12ProMax does in no way negate the pricing argument, it has more to do with demand for a larger screen size.
It don't know what people have said, it's little consequence to me and simply my personal take on it. With the very late release date of the Mini, I'm just hypothesising what contributed to sales not being stellar.
I never understood the "overpriced" argument. Apple has always maintained a $100 price gap between the 4.7" and 5.5" models from iPhone 6 to iPhone 8. There is a $100 difference between the 5.8" and 6.5" models. Nobody complained about the 4.7" or 5.8" models being overpriced.
Now, that same $100 difference between the 12 and 12 mini is suddenly considered overpriced.
Is there any actual logic behind that claim?