Those are 58% off right now, their regular price is $10. The regular price for the lightning version of these Monoprice cables is also $10. Right now i can see a three pack of 6 foot lightning cables on Amazon for $8.40, or $2.80 per cable. The benefit to switching is solely because of convenience and standardization, it is not saving me any money.
I also spent a lot more on some of my USB-C cables because i wanted them to support 3.1 speeds. That costs more if you go for USB-IF certified cables, which you probably should if you’re plugging them in to anything expensive.