There are two places that I known where you can buy:
there is a shop in down town where you can find really everything you need/want in different colours, shapes, sizes etc: buttons, ribbons, beans, feathers and so on.
And very cheap also.It is difficult to tell you how you gonna get there but if you want I can send you an message.
The second one is at the 7th circle: the shop is called She Can and it is at the opposite of the office from JETT.
This is really walhalla but expensive. For more info you can visit the bussines directory.