The most expensive part of owning a pool is the initial installation, which costs between $28,000 and $55,000 for an inground pool, though some homeowners purchase homes with pools already built. Tile replacement is the next most expensive cost (up to $30,000) for pools that have lots of tiles. When it comes to regular maintenance and operating costs, the cost to power the pool’s pump and heater is one of the most expensive parts: up to $300 per month depending on the type of pump and size of the pool.