Today I had the chance to buy this japanese light gun complete in box. It is from 1977 and is called TV Sports Star (TVスポーツスター).
Consulting the Ultimate List of Japanese Video games at http://www.geocities.co.jp/SiliconValley-Sunnyvale/2702/list.html we see that a lot of these video games were released in the late 70's. This also happened in Europe and the US. Everyone wanted in and it doesn't seem like it was a difficult thing.
The rifle sold for 3500 yen, more than I wanted to give. That is around the value of generic early TV-games in both the US and Europe. A bit surpring maybe. There just isn't a collectors market for them, they are considered to be old toys rather than pioneering video games. Especially if they were made by unknown toy companies such as this one. The link says it was published by Takemi (タケミ) but the box says YSA. Neither gives any google hits really.
I might have been able to get 100-125$ for this one, because it's Japanese and has a really cool rifle.