Two suggestions and a plea.
Go to your Seller Preferences/Buyer Requirements and enable a Block against bidders who have Strikes for non-payment. They will not even be able to bid on your items.
Don't use Auctions at all, since with less than 15% of listings Auctions make up well over 60% of Unpaid Item Disputes.
And please don't cancel those transactions, allowing the buyer to walk free but still leave you feedback.
Instead file the Unpaid Item Disputes.
Not only will some slow payers cough up, but those who get the UID Strike will now be Blocked from bidding with every seller who has blocked deadbeats.
And the dead beat can't leave feedback.
And you get your Final Value Fees back.