I bought a cradle for $20 from ebay that we used for Izzy and we just bought a new mattress for it and we loved it. I feel like they are so tiny in a cot and being a winter baby I worried about keeping her warm, whereas in the cradle they seem so snug and safe!!! I know they are fine in a cot too but I do prefer them in a smaller bed while they are so little and this one will be in our room for a bit long too and there is no room for a cot either so I think they are a pretty good investment - even though it is a relatively short time that they are used.