You can enter the castle courtyards and grounds for free, you have to buy tickets to see various attractions within the castle and for audio guides etc. We got the package for about 480 crowns to see Old Royal Palace, Basilica of St George, Golden Lane and St V. cathedral. I’d read several reviews before going about whether to pay to see the rooms, and went with the ‘we’re here so why not’ approach. In all though I’d say the highlight for me was St Vitus Cathedral which was stunning. The buildings were spectacular (just from the outside) and the views of the city were amazing, go into the South Park to avoid the Ques at the photo points, On reflection of our trip I don’t think seeing the castle rooms that we did brought much to our trip. Neither me nor my wife would pay to see the rooms again and would just enjoy the grounds which, as I say were spectacular. Leave at least 3-4 hours. Crowds, school trips and organised tours were very very large.