I'll put in my two bits worth too, having bought a few reamers blind, over the years.
Condition! Amen!
You will narrow your potential buyers down to very few, if you are unwilling to part them out individually, IMO.
More headaches to sell them as 'each' but also potentially a better return.
A couple reamers in tubes will slide into a Express Post envelope for what $10, to the whole country? Around that, anyway. Not an onerous job. Roll them up in a sheet of foolscap, fold over the ends and tape, if there is not a tube for each.
You do not want the edges of the sharp reamers banging against each other in transit. They are cutting tools, and can be blunted quite easily if mishandled.
Make, Caliber, type of pilot (solid, or removable "live" pilot), and any markings that are on the shank, esp. if they are, say, etched on with an electric pencil in a different style from the original markings. (It's not all bad, some of the guys will mark their re-sharps when they go through their shops)
Some calibers have the option of a resharpening, others less so. Worst case, a reamer that has been sharpened already and is small, can be used as a rougher to save wear on the 'good' one.
Cheers
Trev