I visited Tempelhof last month. Not expensive. Handling not needed, but you do get a follow-me to take you to and from parking. Plenty of GA around and only a few commercial flights -- including an old DC3, very atmospheric, and an airship on the grass.
A very well worth while experience, including half an hour in the tower. The controller said there were continous rumour about Tempelhof's closure, but he expected to retire there, in eight years time.
IFR was no problem at all, but I would not advise VFR under a very low cloudbase.
Don't forget your noise certificate. It will save you money.
AA.