Hi Sean.
If you're looking to start selling top-sellers, you'll need to upgrade your account from private to business first. Not only an Ebay requirement, but the law. Private accounts are only for those clearing wardrobes and attics of their old no-longer-wanted possessions. Anyone who makes, grows, refurbishes, or buys in (new or used) items to sell, is a business and must be registered as such.
For confirmation (and to learn everything else you need to know about selling here), go to Ebay's Seller Centre (link at foot of any page). And for full information, go to the government's website.
And note that there is no such thing as a 'hobby seller', and how much or how little you sell or make is totally irrelevant.
@seholds-86
