If you are running a foreign-invested company in Dong Nai and you collect three website quotes, you will likely get three numbers that are far apart. That gap is rarely about quality alone — it is usually about what each quote silently includes or leaves out.
What you are actually paying for
Design and build is the bulk of it. A straightforward corporate site — company profile, capabilities, a handful of product pages, a contact form — sits at the lower end. Anything with a customer portal, a product configurator, or an ERP integration moves into a different bracket entirely, and honest vendors will quote that separately after a scoping session rather than guessing upfront.
Multilingual content is the line item most often underestimated. A Vietnamese, English, and Chinese site is not one site with a translation plugin; it is three sets of copy, three sets of meta descriptions, and hreflang tags that search engines can actually read. Budget for real writing in each language, not machine output cleaned up afterwards.
Recurring costs — domain, hosting, SSL, and any licensed components — are small individually but should be quoted for year two, not just year one.
How to compare quotes fairly
Ask each vendor to price the same defined scope, and ask what happens if the scope changes mid-project. A vendor who gives you a change-request process before you sign is telling you something useful about how they work. One who says "no problem, anything you want" usually rebuilds that flexibility into the invoice later.
The real cost driver
Undefined requirements cost more than any technology choice. A week spent writing down what the site must do — before code starts — is the cheapest week in the project.