If you buy an object for x dollars, then in order for it to be worth it, plan on using it for at least x/$10 hours.
For example, say a game costs $60, then you should play it for at least 6 hours over its lifetime.
The same is true for subscriptions. If a subscription is $10/month, then you should use it at least 1 hour/month.
The ten dollar figure is chosen because that is roughly equal to minimum wage.
Of course, you can buy something and then use it a great amount because you really like it. The ratio of enjoyment to cost is then very large. This is fine. Yet, as a general rule, the budgeting principle holds. One thing though: this rule only applies as long as one has disposable income.