<human>: Can you summarize the given text in a few sentences?

I work in a small office. There is one person in particular that really enjoys planning birthday lunches and celebrating every little insignificant event. The problem is that there is no office budget that she depends on. Instead, she just e-mails the rest with the breakdown of the costs and how much we need to pay her. It is $20/week on average that I have to put out to celebrate the birthdays of people that only yell at me and food I do not eat. 

Today was the last straw: She decided to go buy some breakfast treats and some other "goodies" for "bosses day." I had no clue until I go her e-mail saying how much it was and how much I owe.

I am sure that most of you will be saying "$20/week get over it." Well, unfortunately $20/week is a shit load of money for me. And even if it was just chump change, the principle of the whole thing is just fucked. 

So I ask you, Reddit, how the hell do you "politely" opt out without being labeled as "not being a team player"? Even if I opt out, whoever's birthday is being celebrated will then get upset because I did not participate and it will start snowballing into this huge stupid shit...fucking politics.
<bot>: I am forced to "cooperate" with $20/week for some stupid weekly office breakfast or lunch and not sure how to get out of it without pissing the entire office off.