UNA Market has payment gateways and fulfilment built in, specifically for electronic goods and services but we are updating with extended capabilities for fulfilment / delivery of hard goods very soon. This is more like a Shopify, EBay Snipcart functionality.
Facebook Market does not do this, it merely provides a services for listing, categorising and searching for products, a traditional classified listing - buyers and sellers are then left to negotiate terms and fulfilment on their own - UNA Ads Module is built upon this specification.
Mark P Snipcart takes 2% of each transaction and if it is necessary to add the% for the use of a payment platform like paypal or stripe. is it possible to create a clean module for una which works like snipcart