If you are a designer, then develope those names, and they will quickly gain some value on top of regfee
so as for an appraisal, both regfee currently imho.
brain-zone.info - $x-low $xx. I'll state the obvious too: if you develope it into an informative site with original content relevant to the brain, it will do well on search engines.
brain-zone.info reg fee, but i agree with virgil and think that you should develop it and youll make more of a profit than selling just the domain name
brain-zone.com could get you very low xx. Undeveloped, it is not worth a whole lot. I would set up a website that has brain teasers on it, maybe word problems or games like soduko that make you think. Best of luck with the domain.
if you develop it into something like a puzzle site or arcade gaming site (games related to studies) alot of teachers will use it if it is useful, and the price will go higher
urturn domains reg fee unless you find a right end-user buyer