There's a one-time purchase of bigger/more disks. Figure 1GB (50 20MB pictures) per customer. Just add another 2TB, then 4TB, now 8TB or bigger drive. That's about $250 or $300 each time. Double that for a sync'd drive somewhere in the office.
Now they should be doing 3-2-1 backups. With S3 they'd be paying $160/month (for storage, not counting other costs) for 8TB or $40/month for BackBlaze B2. That's 8,000 customers.
They're in England so some variance in pricing. But it would be relatively inexpensive to buy big drives, sync them to a set in the office, and back them up online. Where the doctors or whoever is running the clinics can SEE the data is still there whenever they want.
I agree that there should be increasing worry about keeping information that you don't need, whether it's intimate pictures of your surgical clients or people who bought from you 5 years ago and not since. But it seems like keeping things handy will be an impulse that's hard to overcome.
TBH DVDs / Blu-Rays are too low density, expensive and labor intensive, and tape drives start at $1000 and most non tech professionals don't know they even exist. 2.5TB of 25 100GB writable BDXL disks cost about $250. A 4TB drive costs $80 and a computer to throw in 3.5" HDDs pretty cheap too.
