WooCommerce

WooCommerce turns a WordPress site into a shop and states plainly that it charges no platform fee and takes no share of sales. The software is free and open source; the money goes on hosting and on whichever extensions a shop actually needs. That makes the total cost a range rather than a number, and the range depends on traffic more than on features. Running it means owning the hosting, the updates and the security, which is the trade against a platform that does all three and bills monthly.

The plugin is free with no monthly subscription and no cut of sales. The real cost is hosting, which the page puts at $25 to $350 a month for most stores and says scales with traffic, and extensions at $29 to $299 a year each. The comparison table lists the platform fee as $0 and the additional fee for using a third-party payment provider as none, which is the row that separates it from the hosted platforms.

Somebody already on WordPress who wants the shop to belong to them, and who is comfortable owning hosting, updates and backups. It is the cheapest option at high volume, because no percentage is taken. Anybody who wants a shop to work without becoming its administrator should pay a hosted platform instead, since the saving here is real and it is paid for in maintenance.