I believe with godaddy domain registration, you get free email with them unless that has changed.
Anyway, if you are just looking for email right now, I would contact them to find out how to use email with your registered domain.
If you are going to build a website or an ecommerce platform, most hosting comes with email so you might want to figure that part out before you get wrapped into the email thing. One of my companies did web hosting, design and SEO. About a decade ago, so … a long way off from what was. One of my favorite client portals for eCommerce was MIVA. Once you get to know the platform it is easy to work with from a design and upkeep standpoint. One of the draw back in the day was the module costs to do what you want to do. But... on the plus side, due to the modules, it could do an awful lot of things.
Not sure what modules are available for exporting to eBay and other like kind platforms - if any - which is something you want to think about if building a platform. Do you really want to list the same item two or more times across multiple platforms. You want a social media connectivity involved so you can promote cross platform on social media as you post items for sale... Probably a lot more.
To me, it is better to have a single portal to shoot out listing across multiple platforms. You need to be able to modify title & description as you don't want the listings all the same if you can help it.
Anyway....my brief thoughts on that.
Cheers
