I have thousands of books, constantly buy more, and have no trouble at all buying them from sources other than the Apple and Amazon alleged monopolies.
Apple wasn't alleged to be a monopoly. Appled formed an illegal cartel of suppliers, all who agreed to fix their prices simultaneously as part of a scheme to raise prices across the industry - by acting in concert to force everyone (all supplier, all retailers, including non-Apple) to adopt an agency model giving publishers the market power to raise their prices. More details: https://www.justice.gov/atr/case-document/file/486701/downlo... - there are clear emails showing how Apple orchestrating the scheme by gaining coordinating and gaining cooperation of all publishers, and then of pricing data showing how consumers were harmed as ebook prices rose as the scheme went into effect. See my other comment in this thread for some choice excerpts from leaders of the companies involved, betraying their conscious involvement.