I was frustrated that they turned from Jimmy to Saul so quickly without showing his progression. He wasn't exactly dealing with the criminal underworld so even after 5 years, he didn't seem to have the clientele to live such an ornate lifestyle. His mentioning the Sandpiper Litigation $$$ was helpful because it explained how he was able to set things up (it wasn't clear on how much money was in the black leather bag).

His clientele before Walt was probably in large part a network of resources and connections for evading legal consequences, moreso than a profit house.