In theory, you should be able to add the BIN items to your basket and pay together with the auction, after the auctions ends with you winning. It's clearly possible that someone else will have bought the BIN items before that point.

The seller should then only get one label - what it will cost, I've no idea. A couple of people reported the postage going down, the more items they bought - eventually to just £1.xx - that was a while ago. Others have reported little or no difference to the total cost. Others have reported that several items have been combined into one label, and the package would then have been too big for the Royal Mail SD maximum. I expect things are still changing on Combined Shipping.

BPF has very little to do with packages insurance/going missing etc. It's for:

• 24/7 customer service: Get support around the clock if you need help.
• Risk monitoring and fraud detection: We actively monitor marketplace activity to identify risk and potential fraud and take action to keep you protected.
• Secure transactions: All payments are encrypted end-to-end and handled by our trusted payments partners.