Occasionally potential sellers come to forums with the belief that if they register for a basic Seller account they can only list one item and seek clarification of that.
I've always been baffled where they gain that impression. Today I noticed this though:
That could be the source of the confusion.
The options could be made clearer along the lines of:
SELLER: Listing occasionally or in low quantities
SELLER+: Listing regularly or in high quantities
This is another of those issues that could lead to potential sellers (future paying subscribers?) just walking away from the site.