It is important to realize that Gio is only in his 2nd arb year. Last year when this deal was kicked around he was in his first. It wouldn't be hard to put together something like 8/12/22/25 with option for 25, including a $5 million buyout and a 3 million dollar signing bonus to come up with a 4/70 or 5/90 structure and be around market value for the type of extension we are taking about.
It would get the Sox some certainty, while still giving Gio a run at FA early, without breaking the bank.