see, in my book at least this is the problem with the whole genre today. if you don't have the patience to wait 30-45 minutes for the shop to open, you shouldn't be playing my game. there's no need to rush in my game, you can't go into it with a "fuck i have to wait for the shop to open, i should be getting XPs as fast as possible, i need max lvl". it's more of a "ahh fuck the store is closed, well i'm a few leathers short of my new tunic I need to make, let's go hunt some shit while I wait for it to open" mentality.
you could solve this problem / add incentive to kick ass in RvR / PvP whathaveyou by having a perma NPC in your guilds castle that you'll always be able to sell to. again, it all boils down to immersion. in my opinion, we need to steer away from the "want it now", "buy it in the AH" gamers that have seriously put a big hurt in the type of game we all are looking for.