There are 3 best possible options to build a multi-vendor ecommerce marketplace:

From scratch - It will cost you very high and you need to have the sound technical understanding to managing the platform.

Plugins & extensions: With plugins or extensions like woocommerce, you can set up a multi-vendor marketplace at very less cost. However, the platform will not be scalable.

Turnkey Solutions - The best option is to choose ready to launch or turnkey solutions. Turnkey solutions are cost-effective & provide great flexibility.

As per your requirements, you can start with Yokart multi-vendor platform. Yokart is one of the best turnkey multi-vendor platforms that comes at a minimal price. For more details, you can visit here: https://www.yo-kart.com/