Ok so my rule of determining the level of difficulty in data recovery is really 2 questions.
#1 - is it making any noise
#2 - is it detected in the bios if you connect it directly to the mobo
If the answer to #1 is yes - then if you want any hopes of recovering the data do not attempt to continue powering it on. It can be making noise because the heads are broken or bent and if that's the case you will scrape the platters and kill the drive beyond any hope of recovery. (data recovery isn't like the way they show it in the movies you cannot actually remove a platter and recover any data off it) And please do not attempt the Freezer Trick - it doesn't work on current drives anymore and actually introduces condensation in the drive that can kill the platters.
If its detected in the bios we can try a couple of things - and i can usually recover the data for about $250 - $799 - over 50% of the time its about $300.