My business is one where folks collect things. And some collect these.
I always leave the cruddy things on the plane, but others collect them.
Even the toothpaste on my SYD flights last month was in a one use flat squeeze sachet.

One member posted here in recent months all the exact colours the el-Cheapo drawstring amenity kits had came in, as he collects and keeps them all.
For the record he listed about 8 colours IIRC.
I mean what would anyone pay on ebay .. a few bucks? Why bother listing it up is the first thought that crosses my mind!