If he's throwing harder than he has in years, don't you think that gives him a very legit shot at being the 5th or even 4th-best SP on the Astros? If they like what they see, why not, assuming the investment is short and relatively small?
Heck, even if Lincecum is only as good as least year, he's the Astros "ace" right now.
There's no indication that he will go for cheap. The hype machine, which he and his dad perfected coming my out of high school, is in full force this go around.