Should I buy some donuts and bagels for the department I work in tomorrow or not?

Here's the deal. I"m in a high rise down in Times Square NYC, Manhatten looking out the window of my corner office and I need help with this situation. So my boss sometimes offers to buy me coffee at Starbucks now and again and I usually say yes, well 80% of the time, and I always offer money. He never acccepts the money, just says "it's on me" and returns with my beverage request. The other day I overheard him offer coffee to my istant, but not me and I was somewhat taken aback by this blatent act, that completely cirumvented my chances of having an warm beverage on such a chilly Gotham City Day...To complete the circle, I have never offered to buy him coffee, but I always offer to pay...So should I offer to buy him some, or just buy a dozen donuts/bagels for my entire department tomorrow, keep in mind that the cost and time that it will take to make that purchase happen is 30 minutes early leave time and $20...What do YOU the general public think?