In my searching for the same reason, I didn't find anything that fit my needs. It seems like most scanners are either cheap and slow, or fast and expensive, with very little in the mid range.
Depending on how many photos you need to scan, it might be more economical (and a lot easier) to have a service like
Fotobridge do it for you.
In my case I just ended up using the flat bed scanner in my Canon Pixma MX922 AIO printer and did a few at a time when I was in the mood. One nice thing about the Pixma scanning software is that it detects separate photos if there is physical space between them and automatically crops them into separate files, so I can do three 3x5 or two 4x6 photos at a time. It's still slow, but it's free and easier than manually cropping everything.