Zero is not close to $99. I'm almost never in a rush for any of this stuff, 2 days versus 5-7 days is not a hardship for me. I have not paid extra in shipping charges. And some items I've bought were not Prime-eligible anyhow.
I was frustrating trying to find things I *need* to fill up the $50 free shipping. I hate "savings" that make you spend more than you would... So I was paying shipping rather than buying stuff I didn't need.
I agree about comparison shopping between prime, non prime, and non-amazon vendors.