Since Heidelberg is a hotspot for tourism we would recommend you to book as soon as possible. Here are a few possibilities which you may consider as your accommodation:

• Jugendherberge Heidelberg
  Tiergartenstr. 5 – 69120 Heidelberg 
  The price starts at 27,90 € for one person a night,
  to get to the E.I. from there take the 32 to Heidelberg Hauptbahnhof
  and the 24 to Rheinstraße
• B&B Heidelberg
  Rudolf-Diesel-Str. 7 - 69115 Heidelberg
  The price starts at 61 € for one person a night,
  to get to the E.I. from there take the 26 to Bismarkplatz
  and then the 23 to Rheinstraße
• Steffi’s Hostel Heidelberg
  Alte Eppelheimerstr. 50 – 69115 Heidelberg
  The price starts at 20 € for one person a night,
  to get to the E.I. from there take the 24 from Betriebshof or Heidelberg Hauptbahnhof to Rheinstraße
• Lotte The Backpackers Hostel Heidelberg
  Burgweg 3 - 69117 Heidelberg
  The price starts at 23 € for one person a night,
  to get to the E.I. from there take the 33 from Bergbahn/ Rathaus to Bismarkplatz and the 23 to Rheinstraße
  Max. 6 persons
• Hotelo Heidelberg
  Czernyring 42-44 - 69115 Heidelberg
  The price starts at 54€ for one person a night,
  to get to the E.I. from there take the 26 to Betriebshof
  and then the 24 to Rheinstraße

If you need further information we will be happy to help you!