You can get estimates from DriveSavers, ActionFront, TotalRecall, etc. (Google or look in the back of any computer magazine) Prices will be many hundreds to several thousands, plus shipping and the cost of a replacement drive.
How is it broken, though? Not spinning, spinning but not accessing, accessing but not reading usable data, visibly burnt electronics on the board?
Twice now I have "saved" drives that had burnt components on the circuit board, buy buying another drive of precisely the same make and model, and swapping the board from the "good" drive onto the "bad" drive, recovering to a third drive, then swapping the boards back again.