Photography is the most comparable thing on this marketplace, because you can see exactly what you are buying before you buy it. A photographer's portfolio is the quote.
Product and menu work is usually priced per session or per number of finished images; events go by the hour or the half day. Retouching is the line people forget to ask about, and it is often where the difference between two quotes actually sits.
Look at a photographer's work in the light you will use it in. Images shot for a printed menu and images shot for a phone screen are lit differently, and a portfolio full of one tells you little about the other.
You say what you are trying to achieve rather than what to buy. Lucy shapes it into a brief, prices it against what people here actually charge, and shows you the creators who can do it. You agree a figure before anything starts. The money is held until you approve the work, and Lucy takes 15% of the creator’s fee — never a fee from you, and never anything on approved expenses.