I've been hunting around for a little shed for the garden and came up with this. It's only 6x4 but that's fine for my needs. It's £89.25 on the website but you can reserve and collect from a local store. If you go to your local then print off a voucher first for a 15% discount which will take it down to just under £76 (hopefully) Thanks to olidea for voucher code.
Link for voucher:http://www.diy.com/diy/jsp/bq/storevouchers/register.jsp?rid=MjI%3D&icamp=HP_teq_banner
Only valid until 30th January, so you'll have to be quick!