Who mentioned a shop? As I understood Junior he was talking about setting up a website.
It is going to be a difficult market to get into, as already stated this is a saturated market. you are going to get into all sorts of warranty, returns and sale of goods issues.
I am all for entrepreneurship (been listening to the CEO of Ann Summers and the co-founder of Coffee Republic today - feeling very inspired) but I would strongly suggest getting some valuable business experience before jumping in both feet first.
A respected relative of mine once told me, "learn and make mistakes with some someone elses money, before starting your own business."
I have recently started an online ebooks business which for a very small investment and risk could earn you some good money on the side. PM me if you want to know more or visit my blog on the subject
http://infoebookstore.blogspot.com
James