We( at webkul ) are the largest supplier of b2b and b2c marketplaces and dropship suppliers based ecommerce tools. Let me share our experience of building the dropship business where offering products from multiple supplier
First of all we need to understand the mapping of product <-> vendor/supplier.
One to One Mapping
This is the case where one product (SKU) been sold by one supplier only. This case is easy to build and if you are using standard Ecommerce platforms like Magento or opencart it can be easily build using following tools
Many to One Mapping ( Single product multiple supplier)
This case is little tricky and hard to build as most of the platforms are built on single catalog system example Magento, Prestashop, Opencart , Woocommerce etc.
Specially when you are following database design patterns like EAV. We have already build the same solution based on popular approach which been followed by various marketplaces like amazon.
This can be easily achieved by using standard tools like
Magento2 Price Comparison