Yes, ebay quotes its final value fee as 13.4% of the final value of the goods plus postage (there's also a fixed fee and a variable fee for selling to an international buyer). As a seller though, I want to know what percentage of the final value of the goods is being eaten up by ebay fees.

Final value: $137.50
Postage: $42.00 (International Express)
Basis for fee: $179.50
Final value fee: $24.05
Fixed fee: $0.30
International sale fee: $1.97
Total fees: $26.33
Fees as %age of Final Value (ie, of $137.50): 19%

So my item sold for $137.50. The buyer is paying $137.50. I'm paying 19% of that in fees. If the buyer had been in Australia and had been happy with standard postage, here's how the figures look:

Final value: $137.50
Postage: $14.05 (Domestic Standard)
Basis for fee: $151.55
Final value fee: $20.31
Fixed fee: $0.30
International sale fee: $1.67
Total fees: $22.27
Fees as %age of Final Value (ie, of $137.50): 16%

The buyer was outside of Australia. If they had asked me to courier the goods, here's how the figures would have looked:

Final value: $137.50
Postage: $96.00 (International Courier)
Basis for fee: $233.50
Final value fee: $31.29
Fixed fee: $0.30
International sale fee: $2.57
Total fees: $34.16
Fees as %age of Final Value (ie, of $137.50): 25%

So the shipping cost, determined by the location of the buyer, and their choice of shipping method, affects the fee I pay, calculated as a percentage of what the buyer has agreed to pay for the goods. The buyer is paying $137.50 and I lose either 16%, 19% or 25% of that, depending on where they are and how they want it shipped. So my question, as asked in my original post, is do people protect themselves against this?