to echo the other folks, despite the NJS parts, that's not an NJS keirin bike since there's no NJS stamp on the BB shell. As far as I know, Matsuri/Nissan did not make keirin bikes in Japan. True keirin bikes are each custom hand-made for the rider by a framebuilder with an NJS license. This is a production / export bike and like others pointed out, the drilling for brakes identifies it as being designed for the road as opposed to the track. Thanks to the fixie fad of the 2000s, buyers are spoiled for choice when it comes to lugged steel track/singlespeed frames. Especially for road riding / urban commuting. Even real NJS keirin frames are usually selling under $500 these days, unless they are one of a handful of the most desirable marques, like Nagasawa / Kalavinka / Cherubim / 3Rensho / Samson.
Complete, I'd value this bike at $300-400. As a frameset, $200.
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