Just saw this at my local 99p store in Swansea. These are retailing at £4.99 RRP, and £4.49 on Amazon for example.
They also had similar Roll & Go art desks in Tesco priced at £6 instead of £12 (although these were Disney Princess themed), which proves how good value 99p is for these!
Looks like many users still aren't aware what '99p Stores' is, they are a major retail chain just like Poundland with over 134 stores nationwide as of early 2010. User 'Lakeside' has posted a list of locations in this thread.http://www.99pstoresltd.com/
Please note the Direct Link takes you to the Poundland site for some reason, and I can't seem to edit it to redirect to the 99p Stores site.
Thanks to mods for updating URL!