This problem is basically the same complaint that was outlined in the Guide entitled "THE PROBLEM WITH EBAY'S 'FIXED P&P' POLICY FOR BOOKS" but in this case applies to items of clothing, mamely 'Coats and Jackets'.
The maximum P&P that is permitted is £4.
However this limit is not sufficient to cover even the most basic postal cost in the case of a heavy woolen overcoat or a leather coat or a sheepskin. These can also be higher value items and the seller (who is responsible for delivery) is wise to a include signed for service.
For example, to post a leather coat wiighing 1600g by Royal Mail's 'Recorded Signed For' service costs £6.60 - and a full length sheepskin would be much more.
If the seller simply adds the cost to the Start Price or Buy it Now price it will simply boost Ebay's commission.
What might be more effective would be a system based on the item's weight, not the the Category. Just as in the case of books, where there are little light books and great big heavy antique books, that all had to conform to the same fixed P&P charge, there are big heavy coats that cost more to send than little unlined short sleeved waistcoats.
Ebay say that they looked at the average P&P cost for different categories. But this is far too innacurate. Some might construe that the more likely reason for setting this limit is to push up the Final Value Price and thereby boost their profit. The buyer will still have to pay more. The seller will build all or some of the P&P into the Start Price plus a bit to cover the extra fee. Poor old buyer.