Couldn't agree more. Your hotel is very centrally located (which is good) but that also makes it one of the hardest to access by car; it's in the middle of the medieval World Heritage Site. The city authority in Edinburgh is unashamedly anti-car. Although it beggars belief, £25 a night for a guaranteed parking space in the middle of Edinburgh is not all that unreasonable.
There are other nearby car parks available, the NCP in New Street, or another facility at St John's Hill. I'm sorry that I don't have details right now; I deliberately took a different route to work this morning to look at the rates sign on New Street but the opening hours and rates were unclear - not least since it is currently next to a major construction site. I'll have another dig around later for you.
But my feeling is that, even if that parking doesn't get you, the one-way streets, the traffic and the temporary festival-related road closures probably will. The city population rises by an additional 150 per cent in August and driving in the centre is not an enjoyable experience.
You'll have fun, though
Enjoy your stay. Will you be in Edinburgh on the night of Sunday 5th for the fireworks concert? One of the best in the world.