Even at those inflated prices storing Google Chrome itself is $0.20. Most libraries aren't 500mb.
If you want to use your device for about 6 years, you have to consider how big these apps are going to be in 6 years. Google Chrome is not going to be 50mb in 6 years.
That is subjective. Yes generally the drive storage is cheap. Apple storage in other hands are not cheap at all and charging a premium for it. Looking in MacBook Pro catalog, they are charging $200 for 513 GB SSD to 2 TB for $800. Most of the SSD of that range is in $50 - $150 USD. Drive storage is cheap, Apple storage are not cheap.