biz is very hard to sell in my experience ( i have no experience with .co ,i totally stayed out of it, but hyphenated .co? even harder imo).
i see many dropped product or service .biz names with xx.xxx exact monthly searches and good CPC, high competition, etc. dropping each day and i don't reg them.
just an example: here is one good key i found today (available for hand reg at time of posting) dropped recently.
but because of .biz, i didn't reg it.
HDMICables.biz 27.000 exact global searches / month - average CPC over 3$