Apple drives are just standard Sata or Pata 2.5 inch drives today, so Wammie has one popular, but not consistent fix.
Others may say put it in the Freezer for an hour and try that, again, it has a history of maybe working.
Best first guess is to take the old drive and hook it up to a pc or Mac via USB drive cable, and if you have any utilities see if the SMART interface can communicate with the device. There are several open source Smart readers this will also give you data about the electronics on the drive.
You can also see if the drive has failed only because a bad or flat bering, that sometimes can be started by a slight jolt.
As far as spending the big bucks, Ontrack Knoll in Eden Prairie will only take a dozen car payments to do the job, but they are good at what they do. There are others that say they can remotely fix your HD, but again hardware Failure does not work with those options.
I have a USB to SATA and USB to PATA cable I can bring down to Free Geek if you want to stop down late Saturday Afternoon, we can see what the system shows up as.
I do not have a system set up with a SMART scanner there, as that is much further in depth than we go to fix things there.
Free Geek is now at 26th and 26th (north west corner across the Memory Lanes Parking Lot, but I am only there Saturdays and it has to be at the end of the day as I am there to help Free Geek with my time, but after 4 I could spend a few minutes to help you and show any bystanders what is a common path to recovery.
If you do come down, bring something to hold the data (thumb drive, or several DVDs)