A web-based online store includes a configurator, a cart, a checkout, and a database, further in which a user interface of the online store enables a custom configuration of a computer system according to an identification of a user belonging to a prescribed customer set. The configurator is provided for configuring a computer system with options selected according to a prescribed user input, the options and a respective pricing for each option being presented on a configurator web page in accordance with the identification of the user belonging to a prescribed customer set. The cart is provided for temporarily storing the customer configured computer system, the cart including a cart web page. The checkout is provided for presenting payment options and for obtaining payment and delivery information, the checkout including a checkout web page. Lastly, the database is provided for dynamically supplying configuration options to the configurator in accordance with the identification of the user belonging to the prescribed customer set. An online store method and user interface are also disclosed.