While an automatic pool cover - often called an auto cover - is expensive upfront, this upfront cost is easy to justify; the upfront cost is an investment, not an expense.
To be clear, if you have an existing pool without an auto cover, one can likely be installed and is highly recommended.
An auto cover is so much more than a mere pool cover.
Safety is a primary reason for auto covers. The auto cover can be closed and locked when supervision is not available.
Of course, auto covers also provide other benefits, most notably savings (money and time). The Department of Energy took the time to conduct a study, where they were able to conclude that auto covers do in fact save pool owners money be reducing the amount of water, chemicals, heat, and electricity that are required to operate the pool. And, since a closed auto cover will keep falling leaves and other wind-blown debris out of the pool, this will save you the time from netting leaves and other debris as well as from having to vacuum the pool as often.
Today, auto covers are aesthetic as they are practical.
And, when the pool is winterized, the auto cover can also be used as the winter cover. An auto cover is a true all-season cover.
You can read the Pool Manual for additional information about automatic pool covers.
NOTE: do the fabric ropes ropes in your auto cover need to be replaced often...too often? Some manufacturers of auto covers will begin offering stainless steel cables instead of fabric ropes.