If we get Hayward/Griffin this summer (give it the likeliness you want), there is no way we spend 90+ million per year in Horford + Thomas + Hayward/Griffin. We have to sign our top-4 pick this year and pay Smart, even Bradley or Olynyk.
If we can't land a top free agent, there is a chance to keep IT with a max deal. However, given his characteristics, I wouldn't offer him more than three years in any case.
If you sign Hayward or Griffin, you absolutely max Isaiah. Cant lose him.
Please could you tell me how are you filling the other 12 men on the roster?
You have very limited money for that, even paying the luxury tax.
You suck it up, pay the luxury tax and fill the rest of your roster with rookie contract guys.
You have no other choice.
Then hopefully you can move Avery for a PF. Maybe Saric?
Then you have Thomas, Smart, Brown, Crowder, Griffin/Hayward, Horford, Saric, '17, Rozier, Zizic all under long term team control. Thats a championship 10 man rotation and then when Isaiah, Horford, and Griffin/Hayward reach the end of their contracts, it should be just about the same time as your next core: Brown, '17, '18, Zizic, Saric, Smart will be coming up for another contract.
If you let Thomas walk it basically defeats the purpose of signing a max guy.