Well, another option is to create a system that could differ wheter a player died on guild wars or against npc\'s. If he died fighting against npc\'s, he would just lose many items and money (no exp), and go back to the starting point, but if he died on a guild war, then it would be like, dunno, he can\'t return to fight on it (supposing that there are special areas for guild wars)
for like, dunno, a couple of hours. Because it would be REALLY sucky if everyone could just go back to fight on the wars after being killed, no matter if he has no items.