Depends on what those $12 "buy" me. In Sony's case, "buying" meant "renting until Sony's license expires", which they could have displayed on the product page.

I very rarely re-watch movies within a few months. So if I buy one, I want to know that I can watch it again in one, 10 or 30 years (if the format can still be played). Which is not guaranteed even with blu-rays mostly thanks to DRM. But what I'd be buying is not having to think about any deadlines.

If I'm okay with a deadline, I might as well rent the movie for a weekend, in which case I expect it to be less than $12.