The pre-negotatiated contracts are clearly the best value in the NBA - a Max guy like Jokic has outplayed his contract by a significant margin, as have Luka, Lebron, KD, etc. The incremental value of their skills - being in the 98th percentile instead of the 94th - is worth tens of millions of dollars more because so few can reach those heights. Rookie contracts, like any sport, are one of the best ways to build depth and raise your ceiling because young guys on a capped contract equal salary sustainability combined with upside. Ownership will never let these go in the CBA because if they had to actually bid on either of these kinds of contracts, Zion would be getting paid $150 million a year.
I think where front offices really show their skills is in the rookie-scale extensions. If you can get guys extended past their rookie deal at a reasonable rate, you're uncovering a ton of value. The contracts that come to mind are Jaylen (a max player probably on any other team), OG Anunoby, Mikael Bridges, Time Lord, etc. Choose poorly here and you can end up with Ben Simmons' contract or Michael Porter Jr's.