What is the appropriate pricing for PowerPoint presentation designs, and is it better to start with the standard rate or an estimated price?

"There is no specific wage determined in Sharia for a worker or craftsman; rather, it is subject to agreement and mutual consent. Facilitation should be sought, and there should be no exaggeration in prices or exploitation of people's needs, for 'May Allah have mercy upon a man who is lenient when he sells, when he buys, and when he demands.' Facilitation is one of the causes of increased sustenance. Therefore, one can start with the lowest prices, or work with what is customary, or make the wage commensurate with the effort and toil, for the more ease provided to people, the better."