It depends on the size of the pond and the fountain. A small, simple pond fountain could be put in for as little as a few hundred dollars, while a large, elaborate fountain could cost thousands or even tens of thousands of dollars. One important factor that will affect the price is whether or not a foundation is required. If the pond is to be installed on level ground, then no foundation will be necessary. However, if the pond is to be installed on an incline, then a foundation will have to be built to support the weight of the water and the fountain. This can significantly increase the cost of installation.
It depends on the size of the fountain and the pond. A small, basic fountain might cost around $200, while a more elaborate one could cost thousands of dollars. A foundation would be used for a house, so it would depend on the size of the pond and how deep it is.
