Some players just don't want to join a guild in order to be able to sell a few items. Aside from the most successful, guilds often have less than the maximum 500 members, even when they have a Trader in one of the capital cities.
What I'm proposing is that guilds that have won a Trader have the option to sublease spots on that Trader if they have less than 500 members.
If enabled by the player guild the option to rent a spot would be shown by the NPC Guild Trader at their booth. The rental fee, set by each player guild would be a flat rate regardless if it's for the whole week or there are only a few hours left until reset.
For example a player guild secures a Trader in a prime location but they only have 480 members who pay 5k gold per week in dues. The guild GM decides to put 10 spots up for rent at 10k gold each and keep 10 spots to invite new members to the guild. By mid-week all ten rental spots are taken but 3 people have been removed from the guild and the GM decides to put 7 of the now 13 available spots up for rent. If all or those 7 spots are rented then the guild would only have 6 remaining spots to invite new members before the reset.
Once rented a guild membership spot is gone until the reset and cannot cancelled by the guild or used to add new members to the guild.
For those who rented a spot the time remaining on their listing(s)would be until the weekly Guild Trader reset, at which point any unsold items would be automatically cancelled and appear in their email as normal.
Items sold from rented spots should probably be kept separate from guild member sales in the guild history listing to make it easier for GMs to manage their trading activity.
As an aside from the above, there have been
some posts about phantom guilds securing Traders, then disbanding and freeing up the Trader if the main guild was unsuccessful in obtaining a Trader for the week. ZOS could implement a system where if this happened the Trader would not go up for “sale” again if abandoned rather 500 spots at a flat rate of 500 gold would be available to rent using the same mechanic as above. This could also apply if a Trader remains available for more than 1 hour after the weekly reset.
As a second aside it would be helpful to have a join guild button on the NPC Trader welcome screen. This would have the guild info, weekly dues for trader access if any and an option to immediately join the guild and would be completely optional.