Am I the only one who doesn't care one bit how expensive the merch is, or if they sell an expensive coffee or not?
If they want to sell overpriced merch or coffee, please, be my guest. In fact, overprice it more if that's what it takes to be able to significantly cut down the number of VIP tickets you sell - or even lower ticket prices. Why? Because these are not things that you need to enjoy the concert and their music and make it an unforgettable experience. I say this as someone who accumulated a lot of merch in my first Green Day concerts and had to leave it all behind when I emigrated and had to pack my life in a 23 kg suitcase. I don't have my old Green Day t-shirts anymore from the previous tours, but I still remember all those shows and how I felt. If you want a t-shirt and can afford it, great! if you can't afford it, you will still have the time of your life at the show, doesn't matter what you are wearing. No one is into Green Day because of their awesome t-shirt designs, it's not the essence of the band. (And I liked the idea of the city badges - something small and affordable and even more special because it's specific to the show you went to).
Same with the coffee. If you love coffee and love Green Day and want to spend a lot of money on Green Day coffee, all the power to you! But you can opt out of that and still enjoy Green Day to their fullest. Drinking their coffee will not make the album or the concert sound or feel different. I for one prefer to buy regular coffee and save that money for the next tour, and I don't feel I'm missing out on a Green Day experience because of it.
They know they cannot be touring like this forever, and want to keep some business going once they retire from touring. And as other have pointed out, tours is where the biggest chunk of the profits come from, since people don't buy albums anymore.