Newbury Comics via Amazon offers Amazon Prime members Superman: The Movie 4-Disc Special Edition on DVD for $5.20 with free shipping. (Non-members can spend $25 or more to qualify for free shipping; otherwise, shipping adds $2.98.) That's tied with our Cyber Monday week mention as the lowest total price we could find by $4. It includes the original 1978 theatrical version, the 2000 expanded edition, three documentaries, and other special features.

Amazon Prime membership is $79 per year; however, Prime is free for college students for six months, and free for parents and caregivers for three months. (Note that currently there's a waitlist for Amazon Mom.)