I just spoke with my Dad today. It was 120 ft, and it was $1200. 00 (dont know how I remembered that??) Over 1/2 was through rock. He said it was $12. 00 a foot with or w/o a (6") casing, and he threw in the last few feet. Turned out to be a 15 GPM well, excellent tasting very cold water. This was over 25 years ago in St Lawrence county NY, I'm sure it would be more now.
Eric