Wiki whatsit has an interesting summary of button history, button like objects were first used a as decorative items (isn’t decoration still the main reason?) rather than fastening. The oldest is a very old 5000 years, and like wool it is a noun which stands for many things including the computer versions. There does not seem to be a collective noun for buttons but I would suggest a box or tin!
The word in English and Welsh (button and bwtwn), come from old French and the latin for button is ipsum. Which I suppose suggests that in the middle ages in Europe, at least ‘buttons’ went out of fashion? More kilts and lengths of fabric with old rope, string and those lovely simple pin broaches?
Today the town of Qiaotou in Zhejiang province China is known as the “button capital of the world” it produces 60% of the world’s supply of clothing buttons. It also makes 80% of the world’s zips. Qiaotou manufactures 15 billion buttons and 200 million meters of zippers a year. It even has a button trade centre!
The US has a button society don’t you know! http://www.nationalbuttonsociety.org but they also call badges buttons so …. and button collectors do not seem to have a collective title – I would suggest a borrower.
The fear of buttons is – Koumpounophobia. Koumpounophobia is a relatively rare phobia, but one that does exist. Do not ask me to say it, or for that matter spell it —but that probably explains why there isn’t a collectors noun – would you want to be a Koumpounist?