Macbook Pro Stuck at Gray Start-Up Screen

Hi y'all. Whenever I try to start-up my Macbook Pro, it gets stuck on the gray start-up screen with the Apple logo. The loading circle just keeps spinning forever.

I've tried clearing the PRAM and NVRAM and the problem remains. I've tried booting in Safe Mode but the problem still remains.

I have a hard drive failure on my hands, don't I? Are there any other methods I can try? Is there a way to salvage the files? If I have to get the hard drive replaced, how much will it cost?

Thanks!

First try repairing the hard drive using one of these methods recommended by Apple:
Resolve startup issues and perform disk maintenance with Disk Utility and fsck