Samsung CU7000 TV Black Spot Repair Issue

My Samsung 55-inch CU7000 model TV has a black spot that is getting bigger on the right side. A technician from Samsung Authorized Service came by and provided a verbal quote of ₺17,800 for panel replacement, hinting that it might be more cost-effective to purchase a new one. After receiving the service report from Samsung, I requested a written quote to submit to my insurance. However, they mentioned that they could only provide it once I approved the repair. When I requested a quote from another Authorized Service, they proposed ₺18,500 for panel replacement. After reaching out to their main office, a representative restated the process. Why do various quotes exist, and why are they reluctant to offer a written quote?