Does anyone have an Ikea mattress and would they recommend? We desperately need a new one but cant afford to be spending a lot on one. The Ikea mattress seem like a good option but I'm not sure what one to go with. It would need to be fairly firm. There's a few around the £100 mark but they only vary in price about £20 odd so i dont know where to go for the cheaper one or would that £20 extra make more of a difference?