White smoke and water out of tailpipe

Sounds like coolant is entering the cylinders. Most likely cause is a head gasket. Other possibilities include a cracked head or block, or some other path through the intake system allowing coolant to be consumed. I've seen coolant passages through the throttle housing leak, and several intakes have coolant passages that can leak into an intake runner. Price depends on damage and overall condition of the engine. Some high mileage engines are not candidates for repairs. Hope this helps.