The First Reply Sets the Terms

Most of what goes wrong in an order was decided in the first two messages, before anything was agreed and while both people were still being polite.

Answer at your own pace

A reply sent within seconds teaches a buyer that you are always available, and you will be held to it. Answering within a few hours is attentive. Answering instantly, every time, sets a speed you cannot keep for long and cannot quietly withdraw later without it reading as a loss of interest.

Give the price before the conversation grows

The longer a friendly exchange runs before a number appears, the harder the number becomes to say. Put it in early, plainly, as information rather than a proposal. A buyer who leaves at the price was never going to pay it, and finding that out in message two costs you nothing.

Say what you do, not what you might

Vagueness early is expensive later. If you do not post to that country, do not offer to look into it. If a custom takes a fortnight, say a fortnight. Every soft answer becomes a thing you are assumed to have agreed to, and the assumption tends to land in the buyer favour, because they are the one who remembers it that way.

You are allowed to end it

Not every enquiry is an order and not every enquirer is a buyer. Some are collecting free conversation. You can answer once, price it, and let silence do the rest. Nothing obliges you to keep a thread alive because somebody keeps replying to it.

Whatever you do first becomes the standard

The discount that got things started, the extra photograph sent to be generous, the reply at midnight. Do it once and it is a kindness. Do it twice and it is the deal, and withdrawing it later feels to the buyer like something has been taken away.