SNK Sale for PSN NA
A wide selection of SNK games for PSP, PSVita, and PS3 are currently on sale. It includes KOF XIII on PS3 for $14.99, and other games from the franchises of KOF, Metal Slug, Samurai Showdown, Fatal Fury, World Heroes, etc.
The sale is happening now here.
Update: Possible end date for the sale is the 17th.