I really don't think people in this thread, generally speaking, understand that the cap will be $100 million in a couple of years, and you need to base a player's market value on a percentage of the salary cap, not a specific number range.
How about this:
Kosta Koufos -- ~$8 million per year
Robin Lopez -- ~$13.5 million per year
Tiago Splitter -- ~$9 million per year
Zaza Pachulia -- $5.25 million per year
When you actually take the rising cap into consideration, Tyler Zeller locked up long term at $8-10 million (i.e. less than 10% of the cap), is a pretty good deal.