While WooCommerce is free to download and install, their extensions are often not free. In fact, for them to operate at optimum capacity, you may have to pay up to hundreds of dollars a year. A popular extension that people get is the additional payment gateway. The more advanced you want your site to be, the more additional costs you’d have to pay. But if all you need is a simple e-commerce store, then a basic WooCommerce plugin would suffice.