If an eBay seller sells their item  for $15.00 Free post ebay takes their FVF on the $15.00.

If I sell an item for $10 with postage costs additional at $5.. ebay takes their FVF on the $10 and the $5 - total $15

Whats the difference? eBay is still getting the FVF on shipping if postage is included in the item cost.

eBay FVF on postage/shipping applies in UK and US also.