How expensive is creation of CloudStorageAccount or CloudBlobClient instances from the point of performance?

Should I create CloudStorageAccount and CloudBlobClient instances every time I want to get blob from storage? For example, I implemented custom Virtual Path Provider for working with a blob storage. What is the best design solution: creation CloudStorageAccount and CloudBlobClient instances once as private fields of my custom Virtual Path Provider, or using of an utility with static (shared) methods that creates CloudStorageAccount and CloudBlobClient instances every time I want to get a blob from a storage? How expensive it from the point of performance?