No one has asked what ought to be an obvious question, so I will. Why waste time with
ebay and all its problems when you can buy good stuff from the APS Stamp Store, and buy it from an entity that stands behind what it sells?
Further, I've bought good Portuguese stuff from the ISPP when it ran its annual auctions. I buy good Mexican stuff from MEPSI circuits and the annual Follansbee auction. I also buy occasionally from two other auction houses and two dealers advertising in the AP & Linn's.
Bottom line: if you take the time to cultivate good relationships with quality dealers, plus the APS, I can't see ever bothering with all the
ebay and PayPal hassles.