Runaway Train by . . . Jay Cantrell has a middle class character who attracts a millionairess.
This is a good read, but if you decide to read this, I recommend that you take some advice that I wish I'd taken:
Stop reading after part 3. I'd rate part 1-3 8 or maybe even 9, but after that I'd give it a 3 or 4. In part 1-3 MC can be a bit annoying and very hypocritical at times, but in part 4-5 he gets real annoying and is acting like a whiny manchild alot of the time. And I'm not talking a little annoying, I'm talking can't continue to read so I had to go and take a walk or do something else because MC is acting like a petulant 3 year old kind of annoying.