you said "In this manner, your cable pair is ALWAYS matched from the same location in the bulk spool. "
that sounds to me like the cable can be mis-matched if take from different parts of the spool. I don't recall matching cables to be an issue with other cables.
My point was though this probably isn't really the case though It seems you said this is what was was told to you as the reason they don't sell bulk wire.
steve