FYI cheap and good quality seldom go hand in hand.
Besides there's many good tutorials regarding making waraji floating around the internet and I've got the impression that most people make their own.
Masamune Date - Sengoku Basara
Sōji Okita (Tsuiokuhen/Trust & Betrayal OVA) - Rurōni Kenshin
*~Next con I'm attending~*
FIN Kitacon (1-2 March 2014)
SAT Keisuke Sannan - Hakuōki: Shinsengumi Kitan
SUN Gin Ichimaru - Bleach