Yeah... Unfotunately, its just a matter of time before failure happens....
Once you get moisture in there the entire unit has to be replaced!!!
This happened to me in 2001 while still under warrenty. Dealers know about it. All I said was I've got some moisture/condensation build up in headlamp and they replaced both!
I actually just noticed some on my passenger side unit recently, so I'll be fixing it again soon as well... Let me know what kind of prices your finding...