That cannot be correct. When listing it said 'simple delivery is not available for this listing as age verification is required and custom postage is the alternative.

Postage is the chosen from the drop down menu for age related postage and listed accordingly. If this was confined to business sellers, it wouldn't have been available.

However, knowing eBay, it wouldn't surprise me, next thing you know is you can only sell black shoes as a private seller , you need to be a business seller to sell brown ones.

Artificial competence at its best!