It sounds like a heck of a deal. Personally, I'd see if I can get the pond deeper if possible. Ponds have a tendancy to fill in over time (or a short length of time like mine did) and having it deeper will lengthen the time until you have to dredge it out again. I dug mine to 22' depth, and within a month Hurricane Ike washed in about 3 to 4 feet of sediment. this winter I had low water going into the winter, and I ended up having between 11 and 12 feet of water in the pond under the ice.
Will the well have enough capacity (GPM) to fill the pond? Will the $$ gained by selling the water be more than enough to pay for the electricity to run the well?