From this point on, players wishing to retire their characters may create new characters, starting at 1/2 of the experience gained since the start of the campaign. As of this blog, that is 10769 total experience points gained; that is per-PC experiences, using party majority for party splits. That means new characters will begin with 5385 XP, plus whatever extra experience they gained from frivolous spending. That will place most characters at level 3, with Airwalkers, Ectomancers, Thieves, and Spies at level 4, and expensive characters like the Dwarven Fury, most Elves, Gnomish Mage, Nobiran Wonderworker, Thrassian Gladiator, and Zaharan Ruinguard at level 2.
As the adventure continues, I will keep a running total of current starting XP. Additionally, once that reaches 20,000 XP, new characters will begin with a flat 16,000 gp, and can trade some of that gold for various magical items, as described on page 253 of the ACKS Core book; at 310,000 XP, it raises to 240,000 gp, and at 640,000 XP, it raises to 815,000 gp. Not that we're going to reach that point in a while, of course...