"iPhone Power Button Malfunction: Warranty Expired, Seeking Repair at Apple Store"

Suddenly, my iPhone's power button stopped working, even though it never fell or got submerged in water. I tried restarting it, but it won't start, and it just keeps showing the Apple logo repeatedly. I've tried everything, including restoring and updating it through iTunes, but the issue persists. Also, my phone's warranty has expired. If I take it to an Apple store, will I be charged for the repair? Because I haven't done anything wrong on my end.