auckland biz - $400 useful for Auckland business directory if developed
authoring biz - $250 useful, but aukward keyword.
bookmark biz - $300 might be useful for a company that makes bookmarks
clinics biz - $400
contract biz - $900+ Probably the best fit for .biz (business contract lawyer or fill in the blank contract software or forms)
cookies biz - $800 Nice for a bakery or cookie bakery as a generic.
discussions biz - $300 Nice keyword, but maybe overly generic for Biz
exhibitions biz - $700 fits the extension for trade exhibit market. Might work for art exhibition company as well.
feelings biz - $200 nice keyword, but I can't think of a good "biz" use.
oncology biz - $300 Nice keyword, but most doctors don't want to present cancer as a business, even though it really is.
You can probably get more on some retail to the right buyer, but above is what I would probably accept as an offer or reserve if you don't get a higher offer in negotiation. I've added my comments as well.
Good Luck.