For a country of 10 million people, the Athens Olympics cost over $11 billion to put on, that's a little over $1100 per citizen.
From the wikipedia page...
http://en.wikipedia.org/wiki/2004_Summer_Olympics It's too much to paste here, but if you go to the link it shows a chart with the current use of all the venues.
Legacy
Preparations to stage the Olympics led to a number of positive developments for the city's infrastructure. These improvements included the establishment of Eleftherios Venizelos International Airport, a modern new international airport serving as Greece's main aviation gateway[13]; expansions to the Athens Metro[14] system; the "Tram," a new metropolitan tram (light rail) system[15] system; the "Proastiakos," a new suburban railway system linking the airport and suburban towns to the city of Athens; the "Attiki Odos," a new toll motorway encircling the city,[16]; and the conversion of streets into pedestrianized walkways in the historic center of Athens which link several of the city's main tourist sites, including the Parthenon and the Panathinaiko Stadium (the site of the first modern Olympic Games in 1896).[17][18] All of the above infrastructure is still in use to this day, and there have been continued expansions and proposals to expand Athens' metro, tram, suburban rail and motorway network, the airport, as well as further plans to pedestrianize more thoroughfares in the historic center of Athens.
In 2008 it was reported that almost all of the Olympic venues have fallen into varying states of disrepair: according to those reports, 21 of the 22 facilities built for the games have either been left abandoned or are in a state of dereliction, with several squatter camps having sprung up around certain facilities, and a number of venues afflicted by vandalism, graffiti or strewn with rubbish.[19][20][18]. These claims, however, are disputable and most likely inaccurate, as most of the facilities used for the Athens Olympics are either in use or in the process of being converted for post-Olympics use. The Greek Government has created a corporation, Olympic Properties SA, which is overseeing the post-Olympics management, development and conversion of these facilities, some of which will be sold off (or have already been sold off) to the private sector.[21][22], while other facilities are still in use just as they were during the Olympics, or have been converted for commercial use or modified for other sports.[23].
The annual cost to maintain the sites has been estimated at £500 million, a sum which has been politically controversial in Greece.[19], though it should be noted that many of these facilities are now under the control of domestic sporting clubs and organizations or the private sector.
