It looks like giving expensive Christmas gifts to bosses is my company's culture. I wouldn't fuss if it is under $20 in total, but they are asking 2 x $30 for the two executives in my company.
The organisers never asked if anyone wants to join in, the e-mail sounded like this is mandatory. I would've ignored it but last year they composed a list of people who paid and sent out e-mail that they know who's not paying.
I don't even spend $30 per head for my loved ones, so I think this is very unfair, considering I don't make that much money. Besides, the presents aren't for my direct manager. If it were for my direct manager, I would shed $30 because he has done huge favours for me throughout the year.
How do I decline politely?
UPDATE: Thanks all for the suggestions! To save the hassle of them chasing me, I sent them a gentle reply e-mail saying that I do not wish to participate this year. Which was replied by a flat "not a problem". It saves me all the stress I'll have to go through for couple of weeks if I were to ignore them.