Advice on opening a small online shop

Hi

I am thinking of opening a small online shop of about 50 products which may expand in a year or so. It is a niche market.
I can't decide whether to go with hosting myself and getting a site built (on which platform?) or going for a hosted, build my own from a template site.

Can you guys give me some advice on what to do. I want to keep initial costs down to see how the business goes.

Thanks for any advice