You've got your interpretation, I have mine. I think you make far too much out of the money. Most of Crockett's paycheck comments were there to make a plot point about the reality of how much cocaine traffickers could make (something that was, frankly, brand new in the 1980s). Also, it stands to reason Sonny would be attracted to women with a certain edginess about them (much like his own), but the OCCUPATIONS they were in (at least in terms of the ones we're given as possible serious relationships, so not Margaret or Danielle) were seen in the 1980s as being very stable. He also wasn't usually aware of the issues his potentially stable women had until after he was in semi-serious relationships with them. He didn't start dating Theresa knowing she was a junkie, for example. As far as he knew she was a successful doctor. And he was similarly blind to Brenda's concept of their future. He was an idealist looking for the stability he lacked, and also wanted to find that stability outside of the Job. To me that's pretty clear. And one of the things we see when he's Burnett is that the toys and money get hollow very fast. I think even as Burnett he was looking for that stability, but in that side of himself he had no idea how to find it.
You also have to take into account the time warp Miami Vice was in when it came to its own timeline. I actually charted many of the episodes in timeline form when I was writing Genesis, and they frankly compress time or jump around in ways that don't work. For all we know he was seeing Brenda for some months instead of the short amount of time it looks like in Nobody Lives Forever, and a Federal payola case would take far longer to play out than what we're shown in the whole Caitlin arc.