colossal waste

Translations
колоссальная трата
Spending so much money on unnecessary items is a colossal waste.
Тратить столько денег на ненужные вещи - это колоссальная трата.
Definitions
A colossal waste refers to an extremely large or significant amount of resources, time, or effort that is squandered or used inefficiently, resulting in little to no beneficial outcome.