Sandy,
I also suggest not to buy網床, since the time for using it is too less may be only 1 months and then you will find it is a waste of area. Since at the very begining, BB like stay in the 網床 because of curiousity and there should be many of toys insides. After that, they do not want to stay there since there is no freedom and they are so smart that they know they will be alone when BB stay in 網床, save$$. May be you can ask TW/MM (second mother) for their opinion.