Utility is a concept in economics that is often not considered by individuals in their day-to-day decision making process. It speaks to the 'usefullness' of a purchase or good that the purchaser receives.
My recommendation when making a purchase is to consider utility from a number of factors.
1. How much enjoyment/benefit will I get from this item?
2. How often will I use this item? Frequently, infrequently?
3. How much increased/decreased benefit will I get by purchasing a better/lesser item, or skipping out on the purchase altogether.
Often we will skimp on purchases that provide regular, day-to-day use and overspend on items that we only make rare or occasional or one-time use. If you are making regular, persistent use of an item, it is better to spend more and get better benefit, and spend less on those items which you will use only rarely (or instead borrow/rent those items). Buying fewer, better things will lead to a higher overall sense of utility.