Season tickets for 2013 have not yet gone on sale, so no one has any to sell.
Current season ticket holders get first dibs on season tickets. After that, everyone else will get the chance to buy season tickets.
THEN after that, regular tickets to The Hunt will go on sale, before the Hunt begins.
THEN after that, towards the end of the Hunt menu, tickets for the Vegan menu will go on sale. I'd ballpark around mid to late April.
There is often little or no advance warning when tickets go on sale.
Your best bet is to set up a Twitter account that sends out SMS, and subscribe to Next Restaurant on Twitter when the Hunt menu is ending.
And monitor their Facebook Page -- Nick will post informational updates frequently.