I would say that the contract extension is far from a given. If Gonzalez asks for too much, they will simply pay Beltre and keep the prospects for a trade for Upton. I don't think the Sox have any intention of trading prospects and over paying. They can simply overpay Beltre and keep the prospects which now have an established market value that is high enough to get Upton.
None of this is true at all. Extension is a given. Its just about the dollar number.
The talk is that Gonzalez wants Texiera money. The Sox wouldn't even give Tex that money, why would they give it to Gonzalez if that is what he looks for. It is no skin off of him to play one more year in SD and then be a FA.
I hope they do come to a fair deal but the Sox have leverage in that if it gets too rich, then can sign Beltre and trade the same prospects for Upton. If they overpay for Gonzalez, they will probably be forced to turn around and over pay for Werth or Crawford.
I think they are more likely to over pay for Beltre and trade for Upton then to over pay for both AG and another OF FA.