Used Mobile resell/repair help

I have sony xperia z3+ bought at 23k which if i exchange is not even going for 3k .also can’t use it since half screen is Not responding to touch..now what is the best way i can do to repair or sell this at higher cost. It has snapdragon 810 chipset and 20.7 mp camera..
Similarly
mi note 4 screen broken
redmi 1s display broken
Moto e power/volume button removed
How can I sell all this mobiles or repair at low cost.
Am not getting proper response from olx too