Would it not be cheaper to buy a brand new (identical) drive, and swap the PCB out of the old drive for the good board in the new drive?
Just an idea - I've heard of this technique being used sucessfully in the past.
Edit: or maybe not -
You cannot do a straight swap of a PCB on Seagate Barracuda 11 series drive. The reason is because the ROM content is adaptive to your drive. This means that it is necessary to physically remove the ROM chip and swap it also. Unless you are good with a soldering iron don't bother - if you damage the ROM chip there will be no way of recovering your data.
http://www.deadharddrive.com/forums/viewtopic.php?t=1196&highlight=7200