I'm pretty sure this "log out at 00:00 SRO time" thing was not intentionally made like that, but rather it's a bug and will get fixed soon enough. Until then, can't you just transfer your for-sale stuff to another account? And judging by the in-game survey, it seems that they are considering some improvements of the system, i.e. making the time run out only during combat.
Hang in there, things are getting better.
