Wet carpet

I recently acquired a 2000 Lexus RX300 with 112,000 miles from my daughter. In cleaning the car I noticed the carpet under the mats was wet - more on the driver side but some on passenger side. My wife had noticed an odor in the vehicle which I had attributed to an over-sensitive nose until I discovered the wet carpet. I dried out the carpet and after driving briefly the carpet was getting wet again. Since it had not rained or the car had not been washed I assume its related to the air conditioning drain system for draining out the water condensed during the ac process. Any other thoughts and how expensive is this to get repaired? Thanks