Earbuds have always been like that (ie couldn't be sold from a sim's personal inventory), I just thought it was by design. With the new multi select option you can now sell earbuds from a sim's personal inventory (see screenshot). Before that I would do as mentioned above, have a sim place it in the world and then sell it from build mode.
Best regards,
Jennifer
(PC: 1.66.139.1020, all packs up to and incl Nifty Knitting, no mods/cc in my game)
No one seems to have posted on this in a while, but I was able to click the 'Select Multiple' items option, and I'm able to sell objects, including the headphones, that way.
