There are 200+ ccTLDs - 'not well known' is relative.
Hard to tell without knowing the TLD in question. If 1-character domains are available it probably means the extension is not very strong.
Its not very strong extension, and you cant reg it through Moniker, Godaddy, or some other so popular registrar. So, what do you think it could be value of single number (not letter) domain in that kind of extension? Thanks.