For an archive this large, doing it yourself with a low-cost scanner is usually not realistic. Community experience suggests cheap scanners can take around a minute per photo or negative, which would make this an enormous long-term project before cleanup and organization.

A practical approach is:

• For the short term, preserve the originals well: keep prints and negatives cool, dry, and dark.
• For digitizing, consider a professional scanning service if you want the project finished in a reasonable time.
• If you scan yourself, expect separate workflows: sheet-fed or flatbed scanning for prints, and a dedicated film scanner for negatives.

For negatives, a dedicated 35mm film scanner with a strip feeder can work well for 135 film. For prints, a flatbed or feeder-based document/photo scanner may help, but scanning both fronts and backs adds time and may require manual handling.

So the key answer is: there likely isn’t a single inexpensive, fully automatic device that will efficiently handle this entire job. Either outsource it, or plan on a very long DIY process with separate print and negative solutions.