Why do you are which part of an assembled computer is expensive nor not? You're buying one piece of computer, not parts. Shouldn't matter if it's the screen, CPU, GPU, case, RAM, SSD, ports or any other part is cheap or expensive.
Just configure the MacBook you want and decide if the price is worth it.
May I politely disagree.
The computer is a summation of parts that work in harmony to create an environment. Those of us old enough to recognize floppy disks grew up knowing that some components can be exchange, such as the CD-ROM, or a hard drive, or RAM. Some people have taken to the level of replacing a CPU. For me, it started with an Apple //e, and since we couldn't afford a second Super Serial Card, I got very good at setting the jumper between modem and printer configurations.
We know that iPads are not computers. Apple told us. I see the iPad as an appliance, and outside of a battery or screen replacement, they are an appliance just like my toaster.
I have come to accept that Apple Management living on Mt. Olympus will not restore the ethernet jack to a laptop, and that I will suffer dongle death because I need the ethernet jack in the work I do. With the desire to be as thin/light as possible, the chances of removable RAM also falls by the wayside. But I find myself insisting on a removable hard drive, and thus I remain on my Macbook Pro 2013.
I have had to send a past MacBook Pro (2007, 17") to Apple as part of the video card repair recall. I removed the hard drive before going - because I didn't want others to access my files, or the possibility that my hard drive could have gone to someone else. It happens - a mixup, and my computer / data is shipped somewhere else. Yes I know I can encrypt, but that can slow down, and is not as a sure thing as keeping the hard drive right here in my sights. Apple may claim soldered hard drives are best performers - ok good, but what about when they die? Or I need more storage.
For cars, I change the tires. Change the brake pads. Air filters. Spark plugs. I will not sell my car because I need different tires. Or if the windshield cracks.
I also look for gently used computers, replace the hard drive, and deploy them somewhere else to be useful (families needing something, college kids, schools). I can do that for some iMacs yet, and the Mini's, but not the laptops. I am good friends with the Open Core Legacy project.
At some point my MBP 2013 will die. I may go with different hardware and either migrate completely to Linux, or Hackintosh.
I wish I had 5 mins to talk with the Apple Board. Show them the orchard that I have purchased over time. And let them know that this all in one soldered locked in crap is not acceptable. Maybe they don't want me as a customer, who has 5 kids that will hit college in the next 7 years. That's a lot of fruit.