Blue/White China

Last ones I promise! As I go through them, I keep finding more and more interesting ones. One looks like a butter dish, another looks like a similar one from earlier, but has a lid. The last one is for serving cream? The marks on these are not as prominent as the others, maybe this means they are homemade or maybe even older than the others? The rest of the collection has alot of chips and are pretty as well but not in the best shape. Is this maybe a hobby she had, collecting blue and white only? Do many people collect these? Are they hard to find in good condition? Rare? Expensive? It is hard to find information on them.