1 Drilling the well hole, installing the casing (a tubular lining that prevents the well hole from collapsing) and adding a well cap (a tight-fitting, vermin-proof top seal) typically costs $15-$30 per foot, or $1,500-$3,000 for a 100' deep well, and $6,000-$12,000 for a 400' well. This brings the typical total for drilling a well and setting up a private water delivery system to $3,500-$20,000 or more, but an especially deep and difficult well with a complex water system can cost $20,000-$50,000 or more, depending on depth, water yield and system complexity.