IKEA have recently changed the sizes of their cots.
They no longer sell mattresses to fit their 'old size' cots.
Because of this, parents who want to buy a new mattress for their old cot are being offered a great deal - take along your old IKEA cot ... in any condition ... and they will swap it like-for-like for a brand new cot.
The only downer is that you have to buy a mattress for the new cot ... but then, you'd need to be buying one anyone, so it's not much of a problem.
Great deal, IMO !