Two item set is a bedding standard. It contains quilt and pillow covers.This is mainstay and you can buy appriopriate sheet additionally.
Thanks to bedding double-items product You can have a few (in easy and fast way) matching by estetic sets - they will be useful for many years
If you buy several versions, you are sure that you will have fresh bedding. Even when baby is sick and some bedding is dirty. You can easily wash quilt covers in every few days. And you don't worry about lack of bedding. Even in winter when everything dries slowly.
If You have a few sets, you can match the colours and motives according to baby expectations. At one point baby will can choose what he/she want or where it must sleep. When we know what our baby likes, it will be easy to provide it.