This depends on a handful of variables...the most important is how deep. Ball park is in the $12 to $15 per foot. Add in pumps, pipe case, tanks etc and the whole "package"may run $10000 for a 400 to 500 foot deep well.....if you get good flow at 150 feet you can save a bit more as far less work is involved.
Contact your local Dowsers Association for help locating where to place the well and what the flow rate would be- cost is minimal. Costs could be greatly reduced!