Replacement Brifters for a shimano 105 2x10 I have a 2009 Specialized Allez Sport C2.  It came with shimano 105 components all around.  the left hand (front) shifter recently broke, and will no longer hold a position.  I can reach down and grasp the shifter cable and pull it, and the derailleur will move, so it is definitely the shifter.  As i understand it, this is a common problem for that vintage of shimano 105's.  I'm trying to figure out how to replace the brifters with compatible components, so I won't have to replace the whole groupset.

new 105 components are extremely expensive, and are set up for an 11 speed rear.  What are my options to just replace the brifters?
The first thing to do is check the brifter out to see if its actually broken - maybe its just a cable broken at the brifter or inadequate cable tension or something. You can get your bike shop to check this out. If it is broken, you can look for people who specialize in refurbishing brifters (they do exist, but they are hard to find). 

As for replacement brifters, any Shimano 10 speed brifter will work on the right (you can easily find 10 speed Tiagra, 105, Ultegra, etc. shifters on the web (I see several at Chain Reaction Cycles, for example)). On the left, you just need a Shimano brifter set up for a double. You can buy just a left or just a right in some cases (possibly on ebay).

Other options are to use something like a Retroshift or bar-end shifters and a regular brake lever instead of a brifter. Microshift brifters are also Shimano compatible.