Electronic stability control doesn't sound like it adds any meaningful costs over ABS. Backup cameras are a cost but not a huge one. What else is there?
ESC in effect mandates the same hardware as the highest end ABS systems and adds throttle by wire on top of that.
Pretty much every AWD car can do "dumb" ABS that uses pedal pressure to run with just the sensors the AWD system uses (front axle speed and rear axle speed) but you need an expensive ABS system with a pump and a throttle by wire system if you want to be able to have the system do stuff when no foot is on the brake.
You can make ABS systems without the pump. They take use the driver's input instead. That's how lots of early systems worked. You give up a little stopping distance in the case where one axle or one side of the car has a ton more traction than the other (think like driving in the gutter of a really strongly crowned road in a downpour) but they work pretty good and are CHEAP, like real cheap.
Throttle control is necessary because you need to lock the driver out of the throttle for ESC. Think of ESC as basically preventing soccer moms from mashing the pedal and getting sideways unnecessarily. Depending on how sideways they get initially the ESC programming is going to want to drag certain brakes to help get everything good again and that requires a pump since the driver's foot isn't there to give pressure (it might still be on the gas).
There's a lot of features that aren't mandatory, but exist in just about any model so they might as well be. It used to be cheaper to get a manual transmission, now there are very few available, and usually on enthusiast models. Very few cars don't have power locks and windows. New cars generally have a touchscreen entertainment system. etc.
Electronic stability control doesn't sound like it adds any meaningful costs over ABS. Backup cameras are a cost but not a huge one. What else is there?