Brignac is 23. Yeah, 2008 was quite poor, but 2006 was quite grand, and 2007 is probably a more accurate representation of what we should expect from Brignac in his career. He took an offensive step back by every stretch of the imagination, yet Brignac still upped his defensive game. A near league average hitter who plays shortstop and is worth 0 < x > 5 runs defensively is pretty damn valuable:
-5 offensive runs
2.5 defensive runs
Adjust those as you see fit, but in the end you're going to wind up with a shortstop worth 2 < x > 3 wins. Hanley Ramirez he's not, but someone like Khalil Greene/Stephen Drew is more realistic. That's valuable.
Jason Bartlett and Akinori Iwamura will be free agents within the next three seasons and while there will always be buy-low and undervalued types on the market, the Rays have a void of internal options behind Brignac.*
Tim Beckham is probably three years away, Chase Fontaine keeps hitting the wall in High-A, and Jeremy "I've got flavor, I've got swagger, damn, I've got swavor!" Beckham is about as much of a prospect as Cody Cipriano.
Unless the Rays suddenly loan Carl Crawford to the Chiba Lotte Marines for some excess cash, it's hard to see Brignac being dealt, especially with a deflated prospect status, and the possibility of starting for the Rays sometime in the near future still quite high.