Social Media Content Creation & Distribution for E-commerce Brand

I'm in the process of launching a new e-commerce brand and am looking for an individual or team to help with social media management. The main requirements are:

Create 1 social media post per day (including visuals and copy).
Adapt and distribute the content across 5 different social media platforms.
Please provide:

An estimated cost for this service.
Information on any additional costs, such as extra revisions or changes beyond the initial scope.
I'm currently speaking with several vendors, so once I have an idea of the expected budget, we can proceed with further discussions.

Let me know if you need more details to provide an accurate quote.