Amazon Does 600 TPS At Peak, Needs 200MB Blocks.

Key word there is "peak" that's why there's a mempool. Also, most people would still pay with some type of credit, and then pay their balance at the end of the month. What percent of amazon purchases are paid from amazon credit and gift cards? What percent debit cards? Crypto would only be used by that portion using debit.

Even with completely full 1GB blocks TODAY:

$5-8 K for a 60 HDD capacity server and $2k a year for 7 hard drives @ 8 TB

https://www.backuppods.com/collections/backblaze-storage-pod-6-0

https://www.amazon.com/Gold-10TB-Enterprise-Class-Drive/dp/B074WH5NPT?th=1

Or get the whole thing put together and set up ready to go for $10-15K (20-30K for 5+ years of full 1GB blocks)

http://www.45drives.com/products/

We will probably have SSDs measured in the Petabyte range by the time 1 GB blocks get to be full.