For the Neo, it's:
+ $100 -> $699 Macbook Neo (well, I probably want Touch ID like my iPad...)
+ $100 + $400 -> $1099 M5 Macbook Air (8 GB feels a little tight, but this new Air has 16GB plus a better CPU...)
For iPhones, currently the 120Hz vs 60 Hz "ProMotion" being locked to higher models, better camera sensors, Face ID etc. iPads also with screen variations, Pencil variants, Face ID, etc. The matrix of available options always have "holes" in the lower models that force you to bundle something you don't care as much about to get a specific missing feature/option at a higher price.