This is just the cost of a meeting. The opportunity cost is a different factor, it's the cost of not doing what the dev would otherwise be doing. Given that yo

This is just the cost of a meeting. The opportunity cost is a different factor, it's the cost of not doing what the dev would otherwise be doing. Given that your not hiring devs to make up hours lost to meetings, the opportunity cost is the cost of not shipping earlier or with more features. The caveat is that this all assumes you know what to build, if you don't attend meetings.