The last time I checked, the main sale allowed the purchase of up to 4 tickets. Since there are so many without tickets (like me), I suggest the limit be two or even just one per order.
Since this sale could be overrun by scalper bots, a 4 ticket limit could allow them to scoop up most of the minimum of 2,500 orders. A two ticket limit One or two would give the greatest chance to all burners without tickets to get one. Two tickets gives you 5,000 people getting tickets, 1 per order gives 10,000 people tickets.
