There are several low-cost eCommerce website builders available that offer great features and functionality at affordable prices. Here are some of the best options:

1. Shopify: Shopify is a popular eCommerce platform known for its user-friendly interface and extensive range of features. It offers various pricing plans, including a basic Shopify plan starting at $29 per month, making it a cost-effective choice. With Shopify, you can easily create an online store, manage inventory, accept payments, and more. It also provides numerous themes and plugins to customize your store's appearance and functionality. (Reference: www.shopify.com)

2. WooCommerce: WooCommerce is a free WordPress plugin that transforms your website into a powerful eCommerce platform. While the plugin itself is free, you will need to consider hosting costs and additional extensions for specific functionalities. WooCommerce allows you to sell products, manage inventory, and accept payments. It also offers a vast range of themes and plugins to enhance your online store. (Reference: www.woocommerce.com)

3. BigCommerce: BigCommerce is a feature-rich eCommerce platform that caters to businesses of all sizes. It offers various pricing plans, including a standard plan starting at $29.95 per month. BigCommerce provides an easy-to-use interface, mobile-friendly design, built-in marketing tools, and secure hosting. It also integrates with popular payment gateways and offers numerous customizable themes. (Reference: www.bigcommerce.com)

4. Wix: Wix is a website builder that includes eCommerce functionality, making it a suitable choice for small businesses. It offers affordable pricing plans, including a Business Basic plan starting at $23 per month. Wix provides an intuitive drag-and-drop editor, a wide selection of templates, and secure hosting. While Wix may not be as feature-rich as some other platforms, it offers simplicity and ease of use. (Reference: www.wix.com)

5. Squarespace: Squarespace is a website builder known for its visually appealing templates and user-friendly interface. It offers an eCommerce plan starting at $18 per month, making it an affordable option. Squarespace provides features like product management, secure checkout, and integration with popular payment processors. It also offers beautiful templates that can be customized to create a unique online store. (Reference: www.squarespace.com)

Remember, while these platforms offer low-cost options, additional costs may arise for domain registration, premium themes, plugins/extensions, and transaction fees. It's important to evaluate your specific requirements and compare the features and pricing of each platform to choose the best fit for your eCommerce needs.