Hi..I am not a powerseller,but after 2000+ transactions,can say that unless your margins are very high ,or your postage costs can be set to recoup some of the paypal type costs,then I would think having your own website makes more sense.
I am seeing e-bay after 2 years trading as a very expensive way to do business.
As with Amazon,and selling second books,its the maximum exposure that it gives you that keeps one using it,but for how long.
Richard Dupont
www.ecoflow.com