In a previous post on average condo fees, Washington DC ranked second with an average of $484 and a maximum (top coded) value of $1731 per month. The data was based on 2008 PUMS data from IPUMS.org.
Using 2007 data from the metropolitan American Housing Survey the average condo fee for the metropolitan Washington DC metro area is $353 and a maximum (top coded) value of $2565. The Washington DC metro area does not equal Washington DC so if the data were subset to just Washington DC, the numbers come out to be $312 and a maximum/top coded value of $895.
However, there are only 146 records for the Washington DC metro area and 11 records for Washington DC proper.
It's hard to choose which data to believe. I would tend to go with the AHS data since the survey was designed to be representative of housing units in the U.S. whereas the IPUMS is a sample of representative persons in the U.S. However, the small sample size for the Washington metro area and Washington DC in particular gives me pause.