Hi
I was fortunate to go in 2000. Such visits are usually organised by churches so firstly I suggest you approach your local Parish Church and see if they are organising a group. It may be that several churches in a district may club together to get a large group of about 40 people togther. The church may use a specialist company like Pax Travel to work out the details of the visit and make the bookings etc.
Our trip was for ten days. We flew from Heathrow to Munich. Coach from Munich to an Austrian Village called Soll - very picturesque - and stayed at a very comfortable small hotel. During the next few days we went on many sightseeing trips around Salzburg, up a funicular railway to the Aachen See - a mountain to lake etc. The Passion Play was on the penultimate two days of the trip. The last day was spent in Munich before flying back.
The whole package (return flights, Coach travel in Austria and Germany, Hotel D, B & B - 9 nights, Passion Play - both days) came to �950 per person. This I thought to be very reasonable.
If the trip is organised properly (as Pax Travel did) then you should really enjoy yourself.