i can't give you a valuation but i do believe it has some limited value. A good number of ascii .jp domains have been registered and are being used with the word "supplies" in it. Obviously, I think the IDN version has far more upside since the use of ascii domain names comes down to historical lack of choice. It stands to reason given the adoption rate of IDN compatible IE7, that in a couple of years, ascii domain names in Japanese will have outlived their purpose. I'd try to sell your name or develop it.