Hosting my "own network of stores (like Etsy or Ebay)"

One of the things that drew me to subscribe to WPMUDEV was the MarketPress statement that says “Multisite compatibility allows you to host your own network of stores (like Etsy or eBay) and take a cut.”

I have done the following

– Installed WordPress in multisite mode

– Installed MarketPress

But I still cant figure how to make it like EBay, where people join, and sell items that can also be displayed on the frontpage.

I was expecting it to be straightforward, but am failing to figure it out.

Is there a simple step by step tutorial or doc on how to do this?

From what I have gathered:

– for managing subscribtions (I use Membership and/or Pro Sites)

– to enable people to sell through their own stores(I use MarketPress, with WordPress in Multisite mode?)

– having shoppers able to browse through stores and checkout at once (Parallel payments?-for Paypal only?… splits payments to the right Merchants?)

– Global Cart is not for sharing a cart across all stores

How do I now get sellers’ items to show on the homepage of the site?

Is there also sample data from which people can get started (like what some other opensource products do)? It really helps one get up to speed very fast.