What changes the scope?
A simple introduction site and a store with payments, customer accounts and integrations need different amounts of work. List the jobs the site must do, the content you already have and the updates you want to manage yourself.
Compare complete proposals
Ask what design, content entry, responsive layouts, forms, testing and handover are included. Separate one-time development from recurring domain, hosting, platform and support costs.
Plan the first release
Agree on essential features first. A focused first version makes the budget easier to understand and gives later improvements a clear direction. Ask for a written, project-specific quote.