I just get around that by mandating a 'BUY NOW' with a 'IMMEDIATE PAYMENT REQUIRED' post.

As for not being able to leave negative feedback, just type 'NEGATIVE FEEDBACK - BUYER BEWARE ! in bold letters when leaving a feedback.

Ebay does nothing about it, and it stands out.
Not to mention you have an option to reply to
your negative feedback if one is left to set the record straight against Scum Vermin.

And I usually have their email addresses, and home address at that point for unlimited payback opportunities !