I took the tour in September 2006, before the hangar was built. I was keen to go as I had been on G-BOAC and my friend had never been on a Concorde.
We took the longer 'technical' tour (not sure which ones they have right now) and that is a smaller group and a longer time talking about the technology. We both loved the tour. I, because of the tecchie and she because it was just so wonderful to be close to those perfect lines. We both loved the visit.
I cannot recall how much it cost but I didn't think twice at the time and have never regretted it.