A three letter .biz I doubt would be available for reg fee.
Generally there is reseller value in .biz and .cc only for the best keywords. Most of the best keywords are already taken in all the extensions, so finding something a reseller would pay much for is not likely.
If the other extensions are taken I would consider .biz for a business website - search engines do not care about the extension. But .biz does not seem to be getting much popularity. Be aware that .biz has some confusion with .bz, and that .cc can be expensive. I am assuming you mean the domain .cc, not any random country code domain, many of which are sleeping peacefully with almost no interest.
For the reseller market there is a strong bias toward .com and, a poor second, .net. That is changing, but slowly.