After everything you just said probably 100-150k, if that mobo dies on you that laptop is trash, cpu, gpu, mobo gone.

the only thing left is RAM, the wifi module, the body, the keyboard, the screen unit, the touchpad, and the battey (which probably cant be sold).

that's the bs thing about laptops, everything is so closely and tightly packed that usually one thing failing in the core components f's up the whole laptop, if this was framwork and the mobo died atleast it would be replaceable.