1-character short internet domains belong to the most rare doamins at all. Even more rare are ccTLD 1-char domains!
Here for sale:
a.sv
Real Latin-1 charset top 1-letter "A" - no punycode trick.
Beautiful extension .SV that can relate to "Server", "Service", "Silicon valley", ...
Good renewal price at 80 USD/domain/year including trustee service.
Sale and details:
http://1-single-letter-domains.com/?r=list21-asv-pb#1chars