So, Tim Lincecum, two years, $35M.
Here's what I think. It all comes down to one thing: is Tim Lincecum likely to be a reasonable rotation starter for the next two years?
If you think so, then...well, yes, he's overpriced, but it's better to spend $17M on a $10M starting pitcher than to spend $10M and give 20+ starts to a guy who shouldn't be on the roster. Sabean was looking at three open rotation spots; there's absolutely no guarantee that he could have filled all three with guys you want to take the ball 33 times each at any price. At any rate, if he's a league-average starter than $35M/2 years is high, but not outrageous; there will be much worse contracts for pitchers this winter.
On the other hand, if you don't want him to make 66 starts over the next two years, regardless of price, then it's a bad signing.
It's really that simple.
So do the Giants want Tim Lincecum to be a rotation starter in 2014 and 2015? It's not clear, from the number. He's coming off a year with a 76 ERA+, and before that he was at 68 ERA+. That's not good enough, so the question is whether he'll be better. And I think there's a reasonable case for it. His K/9 is still a very solid 8.8; his unsustainable BB rate spike from 2012 disappeared in 2013. He didn't exactly do clearly better in the second half of the season, but there's at least a plausible case to be made that there was improvement.
It's probably worth noting that he's been extremely durable; of course, that may not last as he gets older, and is only worth anything if he's better than he has been.
Is it wishful thinking to think he could build on what success he had in 2013? Maybe!
There's also a part of this that really does go past the stats. The Giants are in an excellent position to see beyond the numbers. There are risks at that kind of scouting, but there are opportunities as well, and I think it's reasonable to give the Giants the benefit of the doubt on that kind of thing, especially with pitchers.
If they gave him the money because they thought it would sell tickets, it's a mistake. There's no way a mediocre Tim Lincecum is going to sell more than a few season tickets at this point, and he certainly won't help specific game sales if he slumps from the beginning of the season. And at any rate, it's not even close to worth risking a postseason appearance over.
But if they think he's a league-average pitcher over the next two years, and that given their position it's probably a good idea to overspend for a league-average pitcher right now, then it's a reasonable move. As long as they're right about him bouncing back just a bit more.