Any question answered...

That depends on why you are unable to extract the data.

If you're lucky, you can recover using software - zero assumption recovery is my go-to app for this.

If you need something a little more base, you may find that the disk manufacturer provides recovery software.

If you go to a shop that does software recovery, be sure to insist that they do not open the drives. They are very likely not set up to do this, ands can easily ruin the disk for future attempts.

If it's (non-platter) hardware related, a donor drive may be of use - the platters can be swapped over (in a clean environment). But you will need the donor drive to be as close a match the original drive - as in the serial numbers being close, not just the same make and model. I've used Kingdom Data Recovery in Scotland - it's a couple of hundred for a successful recovery, if you have a donor drive.

If it's platter related, you could be looking at spending thousands.