Peter,
If the funds are in your account, the funds are YOURS according to Paypal. I have spoken with them on this subject after starting a new Seller ID and having a Hold put on a $500. payment. I was the "0", the buyer was 100%. The payment is held for "UP TO" 21 days BUT (if read carefully) is released after buyer leaves feedback or when the shipping is done through Paypal (which I do) and delivery noted by them. My $500. item was received in two days, buyer left feedback and the funds released within 24 hours after that. About 4 days total, not 21 days. The funds are yours but not available to use until one of the terms is met. I guess it is up to you on how you want to approach the "0" buyer. Everyone has to start somewhere...on eBay we start at "0".
Jay "sometimes aggravated by rules too" Dubiel Halifax, VA USA