Why one number is a risky answer
When you reply with a single price to a vague request, the client compares that number with everything else they have seen, without context. If the price is low, you have set a ceiling. If it is high, the conversation often ends before you can explain what the client actually gets. The number is not the problem. The missing scope around it is.
Name the scope before the amount
Write down what the work includes: the concrete deliverables, the working time, how many revision rounds are inside the price. Then write down what is not included. Exclusions feel uncomfortable to write, but they protect both sides: the client knows what sits outside the price before they accept, not after.
Show assumptions instead of guessing
Most price surprises come from silent assumptions. Say openly what you assume: the client delivers materials on time, the text has one approval round, the project covers one language version. If an assumption fails, the price conversation reopens honestly instead of turning into a conflict.
Give options instead of one price
Two or three options change the question from 'is this worth it?' to 'which one fits?'. A smaller option with a tight scope, a standard one, and a wider one for clients who want more of your attention. Each option needs its own scope, not just a different number.
Ask before you promise
If the client's request leaves out things that change the work, ask before quoting. Two or three concrete questions look professional, not hesitant: what does the client already have, who approves the work, what deadline is real. A price sent after those answers holds much better than a fast guess.
Reply in a message the client can act on
A good reply has a short structure: what you understood from the request, what the service includes for which option, what is not included, what you assume, and what you need from the client to start. End with a clear next step instead of an open question.