Konan Angel -

Lowest price ever 167, Average 235

Grudge Kakuzu -

Lowest price ever 155, Average 183

Bee 8tails Chakra -

Lowest price ever 165, Average 188

Most new ninja are released for ingots first, and I only track coupon prices. But, Here is the what I have for their first coupon price:

Bee 8tails Chakra - Sept 6, 2018 - 175 and pretty consistently around that price

Angel Konan - Apr 19, 2018 - 233, consistently between 230 and 250 until late this summer when it dropped to 200 and continued to drop

Grudge Kakuzu - Before Nov 23, 2017 (when I started recording data) - 210, consistently between 180 and 200, dropped to ~150-160 in the last month