A locksmith can definitely do it!
I bought some doors from a junkyard and I wanted the locks matched to my existing key. I found a locksmith who did two locks for $20.
Here's my advice - go to a junkyard, if possible. Get the cylinders from the doors, then take them to a locksmith.
Now.....getting the cylinders out can be a little tricky if you don't know how to do it.
First, there is a little plate ("door lock cylinder retainer") holding the cylinder in place. Once you get the panels off, use a screw driver to push the door lock cylinder retainer up (
http://www.teamcherokee.com/Locks_and_Keys/index.html).
Once the cylinder is loose, you have to feel around inside for this little plastc "holder", if you will, that hold the metal levers in place.
These metal levers connect the cylinders to the rest of the locking mechanism.
Basically, these holders are plastic "C" clips that fit around the levers and hold them in place. Just apply a little pressure and they pop right off. Then you can pull the whole cylinder out along with the lever.
Now, these "levers" are connected to the cylinders with very tight "C" clips.....so it's better to just slide the whole thing out through the front of the door.
Once you practice getting these out in the junkyard, you will figure it out really quick. Again, just feel for the plastic clips that are holding the lever - and pop them off.. After you push the retainer off......the cylinders will slide right out.
Then a locksmith can hook you up real quick.
BTW, you may have to ask around for locksmiths to match your key... Some will give you ridiculous prices for this. But eventually you should find someone who can do it for very little... If I remember correctly, it only took him like 30 minutes to do two locks.