Vendor fees make no sense at all. If you live away from Luna, you cannot afford to run a vendor for long, as the daily fees soon consume your selling price. Even in Luna, with the shopping traffic nowdays, fees are prohibitive. The goal of the Devs should be to encourage trade, not restrict it. Perhaps a transaction fee would be more appropriate. A one time fee at the time of sale would at least allow you to put up expensive items for sale at a reasonable price.