The Trading Post is for commercial sellers (traders) only.
Member Classifieds is a place for Full Members to sell on their gear to BCUK membership.
Makers Market is for hobbyist makers to sell on their goods.
Your E-bay has items that fit both in Member Classifieds and in Makers Market.
Depending on the amount of stuff you plan to make (beeswax candles, etc.) you can suffice with being a FM, otherwise you'll have to top up your subscription and become a Maker.