How to Save £20 at IKEA

Last night the flatmate and I, as part of our "Flat Rejuvenation" project, spontaneously went to IKEA to get a bookshelf...as we were leaving we decided to check out the "as is" section, and came across exactly the shelf we were about to buy, but already assembled (with no obvious flaws), and £20 cheaper! From that point it was only a matter of fitting a very long shelf into my very short Amica and trecking it home on the North Circular. The Flatmate's father was wondering if we got a £20 ticket, but no, we made it safe and sound!