1. True for mainstream books, absolutely not true for academic special interest titles. Many books simply aren't available - including some still-in-print titles from academic publishers.

2. Ditto. Pricing algos and greed can do insane things to prices. When I needed one out-of-print academic title recently the copies on Amazon were going for four figures. Luckily the author had uploaded a PDF to his web site.

For other books I've looked at, three figures aren't rare. Communicating with sellers directly has sometimes brought the price down to something more reasonable - a sale now being worth more than a listing that may take years to pay off.

3. This part is true - pay, wait, receive. Although it's not infallible, because some of the bigger sellers play an arbitrage game where an algo checks possible sources for tens of thousands of titles and then if found, adds a percentage to create an auto-listing. I've had orders cancelled when this process has failed, for whatever reason.