The Viennese start-up Zoomsquare has developed an interactive map, which you can use to find out if you can afford a flat in a certain district of Vienna.
To do so, simply click on this link, enter the maximum rent (“Max. Mietpreis (€)”) and minimum numer of square numbers (“Min. Wohnfläche (m²)”). The map will automatically show you the districts in which you can afford to rent (or buy) a flat. To get a brief impression, have a look at the metro map (pictured above), which shows the average prices per square meter near certain metro stations.