Hi @san04 I take it you are out of Warranty. It very much depends on the issue, know though that over a year ago one customer was quoted £150-200 just for Backlights ,screen replacement obviously more. You could get in touch with Samsung support or there is a Troubleshooting tool here https://www.samsung.com/uk/support/repair3/
Depending on the issue and age of the TV need to consider if would be worthwhile.
I do not work for Samsung or make Samsung Products but provide independent advice and valuable contributions.
My Device- S21 Ultra 5G ( SM-998B/DS ) CSC= BTU , 12GB/256GB One Ui 5.1,Android 13 .