Interesting comparison.
That said, why are you comparing an "upgrade" for PCs (meaning that you simply buy the RAM and SSD and do all the installation and replacement work yourself, which is after the fact) with the "upgrade" when buying a Mac (meaning that Apple actually builds the machine to your specs from the beginning or ships you a pre-built unit with those specs—you don't have to do any replacement or installation yourself)?
I get what you're saying about the price difference, but it does seem like the comparison is not quite apples-to-apples, or oranges-to-oranges 🍊 In Apple's case (at least with the laptops), you can't do anything once the unit is shipped to you, but the unit comes already "upgraded", which saves you the hassle. With a PC, you do all the installation and replacement yourself (which is generally not hard anyway, if you have a screwdriver and a little time on your hands), unless you order the unit with the customized specs you want beforehand from the manufacturer or retailer.
To make a better comparison, why not compare similar Apple and PC models with the same base model RAM and SSD specs, and then show the prices you would have to spend for each if you wanted to upgrade them at the manufacturer from their base model specs? (Most PCs likely still come out cheaper than Apple in this case, I imagine, but this is just to be fair.)