Why is AddItem returning this error message - You have entered invalid minimum bid or Buy It Now price, when I try to list a StoresFixedPrice Item?
If you want to list a Fixed Price item where the ListingType is StoresFixedPrice or FixedPriceItem, you must specify the StartPrice and not the BuyItNowPrice. If you specify the BuyItNowPrice, you will get the error message. Please see the documentation
for more details on the ListingType and BuyItNowPrice.