Cost is what is spent.
Value is what is earned.
Cost is time, money, energy, lost opportunity, reputation, etc.
Value is time, money, energy, lost opportunity, reputation, etc.
Some things cost a lot, and have little value. Some things cost a little and have a lot of value.
Sometimes, you will face a decision between: something that costs a little and has a little bit of value, and something that costs a lot and has a lot of value.
The decision can not always be systematized. In other words, it is often situational.
Be aware, that when you decide to move with a decision that has little cost for a little bit of value, a(n opportunity) cost of that decision is the value of the declined decision.