Failing External HDD

Hi

I've been googling like crazy and need to know what my options are.

I think I have a failing external HDD. WD Passport 500gb 7200RPM. The last time my disk was able to successfully mount to my mac, it was making weird noises. I tried transferring my files off of it but got an error message, something about removing .DS_Store. After disconnecting my HDD, I haven't been able to remount it after plugging it back in.

It doesn't mount, but it does appear when I go into Disk Utility. I press verify, and it tells me it needs to be repaired. I attempt to click repair, and it says that it is not repairable and to format it (which I'm not going to do). Error message says "invalid node structure."

Should I use Diskwarrior to repair my drive since DU can't? Or should I be consulting pro data recovery specialists? I don't want to shell out $120 on diskwarrior if I don't know for sure this is what I need to do.

Should I try to clone this disk to another drive that I know works? Will that work or do I run the risk of losing my data forever?

I am going to get my drive diagnosed by a data recovery place in my city, but until then, I just want to make sure that there is hope in recovering my entire disk and I won't be paying an arm and a leg to data recovery specialists.

Thanks so much for your help

Ryan