Hard drive corrupted - what can I do to recover it?

I had my external, USB-powered, hard drive plugged into a non-powered USB hub. I also had a USB-to-Optical adapter connected. I then stupidly plugged in my iPhone, and then I heard clicking sounds from the drive. I immediately unplugged the hard drive and dismounted the drive.

When I plugged it back in, it was showing as raw data. I attempted to do a chkdsk /f /r on it, which was going painfully slow on stage 4, but then it completely froze up (I left it running for 24 hours with no more progress at around ~32000 out of 44000 files). I turned off my computer, and tried the same, except this time it froze much earlier.

Is there anything else I can do? I'd be willing to pay for some decent software to get the data back, but I'm not desperate enough to spend ~1000+ on data recovery services.