The Greek was on the level of the cartels. Gus was making millions but he still had to deal with them for their major cut until he made his revenge. Plus, Avon was based on the real lives of Nathan Barksdales and Melvin Williams who played The Deacon on the show. Those ex-drug lords had close to a net worth of 100 million. Just like with Gus, Avon had SEVERAL fronts too as well as controlling both housing projects on some Nino Brown shyt. Not to mention the political connects which Lester were obsessed with because lord knows how much $$$$$ Avon was channeling.
He had enough to hold his own family and his peoples WHILE in prison for several YEARS until that well finally ended up dry.I can safely assuming during his peak years he and Gus were even. The GREEK was on some OTHER level.
Ok now we got some numbers to work with.
If their net worth was $100 mill then Avon was nowhere near Gus. In season 3, episode 9 Jesse comments that the $3 mill Walt got from the deal with Gus is "bullshyt" because Gus was making $96 mill in 3 months. That's Gus's money, he built the lab specifically to circumvent the cartel, remember?
And I can't really agree that The Greek was on the level of the cartels. The Greek was supplying neighborhood drug lords, the cartel was supplying Gus who had distribution in 6 states (again, season 3, episode 9).
So in terms of power it would go: The cartels > Gus > The Greek > Avon. After the cartels were cut out, Gus would be the lead. Then Walt.
Fred.