Firstly sailor can be mid-late game so it isn't just some 3*.
Secondly, tell me a ninja that is more than 3* and you can auto buy.
Thirdly and lastly learn to do basic math before you try to correct someone. If she is 20% off at that price that means she is still at 80% of her price so divide her price by 8 and multiply by 10 and what do you get?
You get 50 per frag.
What is 50 x 80?
50 x 80 = 4000.
So you DO pay 400 more.
To conclude, in Konoha Gift shop (I believe) might also be others she was 45 per frag like I said. Hence, scroll up and re-read what I wrote.