You have some nice items for sale, but do they really need to be in auction format ? Surely also you may reach more sales someone wishing to buy trainers or handbag may wish to buy, pay and receive the item sooner than wait for a 7 / 10 day auction to end.
Most ( all ? ) of your items have a ' ceiling level' for price, so you can list these in a Buy it Now format and select ' Immediate Payment'. That should cut out the majority of non payers.
When I was selling I found the majority of non payers I received were for auction ended items. I imagine peeps may not watch auctions ending so may not realise they've won and need to pay, or even forgotten they bid for an item 7 / 10 days ago ? 🤔
@roxyranger