A average home with an 1100 square Inch Roof will gather you about 200 Gallons of Water a year here in Indiana annually. Just for your information...
I thought it would be much more than that. I might start with one or two because if that is all I get it won't be worth the cost.
I wouldn't say I am set on the idea. It all depends on cost, work involved and how well it will work.If you are set on having a Well, then I would go with a Spike well and put a Hand Pump on it...