Tech Help: Difficulty of Building an E-Comm Marketplace?

Hello! I'm looking for advice and to get a sense of the difficulty and cost of building a curated e-comm marketplace. I'm a creative and don't have many tech contacts. I've explained this idea to a few different people and I've gotten wildly different answers from - oh you should be able to find no code tools to do that - to - oh you're going to need several million dollars in funding to do that. So, I'm just seeking some further opinions and hopefully clarity!What I'm looking to build:A curated e-commerce shop of branded fashion & beauty products that actually functions as a marketplace that holds 0 inventory - all fulfillment is completed by the the brands themselves, which each have their own e-commerce shop setups (let's say mostly Shopify). Basically, inventory from all their individual shops would need to be integrated into this one curated e-comm platform. Ideally, payment would be completed on my platform, but an MVP could involve simply syncing inventory and linking to complete purchase on the brand's own platform.Similar platforms that already exist:Garmentory https://www.garmentory.com/Farfetch https://www.farfetch.com/Wolf & Badger https://www.wolfandbadger.com/usBubble https://bubblegoods.com/What I want to know:How long would it take to build something like this? Like...3 weeks, 3 months, 3 years?If I were to hire someone freelance to build this, approx how much would it costIf you, or anyone you know, would be interested in working on this with me as a cofounder/partner, let me know! I'm ideally looking for POC / WOC.