I think you're mistaken with your calculation Davewil

yes 9.9% of $120 postage to Canada works out at an $11.88 ebay fee on postage.

Now if I had charged my customer $131.88 postage, the ebay fee would have been $13.05

So to not leave myself short, I would have to charge my customer $133.20 postage so as to cover the ebay fee on postage being $13.18 leaving me with $120.02 to pay the postage.

Like mentioned earlier, ebay need to have the % postage added on to cover their fee or give us new chart to show us what we should charge for postage to cover the new fee ie: charge $14.90 for a 1kg satchel so as to account for the $1.47 ebay postage bringing the cost to the seller back to the price they pay at the PO - $13.40 etc...