Unit 1: The price of handbags

This BBC clip says that a handbag is now the most desirable and fastest growing accessory

< http://www.bbc.co.uk/mediaselector/check/nolavconsole/ukfs_news/hi?redirect=st.stm&news=1&bbram=1&bbwm=1&nbram=1&nbwm=1&nol_storyid=6217193 >

a) Why has demand increased?
b) Limited editions sell for considerably more than the "normal" version. Use supply and demand analysis to explain why this can be the case