You’re right that there’s a cost to it in money and space, especially if you’re starting from scratch. Luckily I never liquidated my movie collection like others have, so it’s much easier to tend to it casually. I almost always acquire titles either very cheaply secondhand at thrift stores, Half Price Books, etc, or as gifts. Much of the pleasure comes from discovering things serendipitously, as opposed to just immediately buying from Amazon.