Ebay roundabout

Being relatively new online and only just discovering the joy of broadband I am now discovering a whole new world. The first curiousity is ebay . In particular I am intrigued by those compulsive posters/sellers who source their own stock from other inhabitants online. How many times would or could a single item go around the cyber shopping mall? After the next house clean out I might conduct a scientifically based experiment to try to find out. Just not sure that the BNWT size 22 yellow t shirt I saw listed for 9 cents could survive even the first round!