Well... I didn't bring ice cream sandwiches. I brought ice cream bars. Last year I spent about $30. Budget isn't a big deal. I'm willing to spent in the $20 to $50 range. Last year, there was roughly 30 people. This year it'll be nearly double (lots of new hires). I don't have to buy for 60, but I feel I should focus more on quantity instead of quality.
Lots of good suggestions so far, but many coworkers are Costco shoppers and have already signed up to bring most items mentioned. The rest will pick up pizza or chinese takeout from the food court. And there's always someone bringing samosas.
The viet subs is a good idea, but I would need to pick them up really early in the morning (7am). I don't know if they open that early.
I typically like to bring something that you don't normally see at potlucks, but with no kitchen and either be bought the day before or fresh the day of (but before work), really limits my options. Right now the front runner is picking up 3-4 dozen donuts at Krispy Kreme.
Storage locker is surprisingly well stocked. We have more forks than pens.