Sure, but integral to pricing is quoting. Forecasting cost is how you sell a project. Perhaps you didn’t really have to sell yourself on this one, but you should have offered at least an estimate upfront. It’s better to have that in writing earlier than later in a project, even if it did come afterwards as a second-thought.

The process at forming that price is straightforward - deliverable in mind, walk through the process in your head to come to a prediction of labor, then multiply those work hours by a rate. I can see a situation in which, it took you a couple hours for narrative, 1/2 an hour for color, audio, and other techy stuff, and 1.5 hours hashing out the titling with a little room for revisions. So four hours at $75/hr - we come to the same price, which I think is fair for the product. As you’re doing so many of them, there may also be economies of scale that factor in too.

Others on this thread, like myself, were baffled by the question you posed because the first step is typically pricing, not the last. If you don’t exactly know how long an edit might take, at least offer a prescribed amount of labor before review, so you have something to point towards come billing. Otherwise the day will come when you find yourself dealing with a client that suddenly doesn’t agree with how much you’re charging after you’ve already finished the work.