My parents have been scanning in all their ancient photo albums, from the day when adhesive-backed pages were used to hold the photos in, and then cover them with a plastic sleeve. Now, of course, it's all glued shut. Sticking the whole mess, one page at a time, onto a scanner works well enough. Given that many of the original photos were taken with a Kodak Instamatic or equivalent, there's not much point in going overboard with high resolution scanning, when a cheapo plastic lens was being used in the first place.

What is valuable, though, is getting good bit depth per pixel. Older color pictures have fading issues, and you can recover most of that in Photoshop with some amount of effort.