The default items shown in the Marketplace with a category/subcategory filter are flawed. Especially when ShowUnavailableItems is factored in, and there’s a big discrepancy between logged in vs. not logged in.
Logged in | All Accessories
Logged in | All Accessories & Show Unavailable
Logged out | All Accessories
Expected behavior
Free items, though they have the highest sale volumes, will not dominate the top few rows returned by the catalog API. Additionally, for non-logged in users it will have similar functionality to that of logged in users (i.e. either showing or not showing free items the first few rows with the same parameters)