Yes 275 is a lot. But that is brand new compared with this. Box is beaten and its used. So for collecting sake its worth it. But don't mod it that is too expensive. Get another jr for modding sake and leave the new one alone.
And a good switch box does make all the difference. I have verified that. The above even works on my nes and gives better picture than my original nes automatic switch box. Was also considering one of these. Looks a lot nicer than the other tiny box I have.