Replacing the IR board is extremely simple. It takes more mechanical skills to mount the TV to the wall, than to do such a simple fix.

Just triple check to get the correct IR board for the TV before ordering one.

Repair shop is going to charge a few hundred dollars to do this. $15-$29 for the board and $200+ profit for less than 30 minutes of work. Maybe an hour if you count taking the TV down and putting it back up again.
No reason for you not to make that money, instead of the repair shop.