Ok cutting the fun part out and getting serious , I have found one fool proof method in addition to all of the above listed ....very simply email the buyers , not the seller , mant ebay buyers especially are good old RC guys like you and me and as you know we love a forum .They will tell more then you need to know about the seller and quality of the goods .

Back to your original post , I have aprox 15 rc sellers saved , as a result ebay now emails me "a favorite sellers update" when they add products .
I get emails from everything on century jet retracts to kit planes to ARF warbirds .