Two black lines across middle of screen. I have two black lines running across the center of the

Question

I have two black lines running across the center of the television when it is on.  I hand delivered it to Olevia in SoCal.  After weeks of calling them, they finally told me it was the main board in the television, and it would cost $350 parts and labor to fix.  (I really think they just threw a price at me without looking at it).  I want to know if something like this would be cheaper if I brought it to a repair center instead of the Manufacturer.  They run for around $900 now so I'm wondering if it is even worth it.