If you want to chase bids on an open freelance site, I'm happy to recommend
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Just give as much detail in regards to design and function as you possibly can up front to ensure an accurate quote. If you take on a developer without them having all the details up front, then your price can blow out along the way with them having to make constant unanticipated modifications.
Of course don't forget the Salehoo Stores platforms either, one of those may be a good fit for you if you don't want to build full custom from scratch.