It's a great place to ride. The cheapest gas is in I'm thinking Stove pipe wells. One variety. Furnace Creek is significantly more costly. There is no gas at the castle. I ran into construction on the road to Scotty's castle when we went about a month or so ago. They stopped traffic for about 15 or 20 minutes. We decided to go elsewhere instead of waiting, we understood there was additional stops ahead. I enjoyed the lunch in Furnace Creek, bit pricey but plenty to eat.
They only charge 10 for bikes, even with two people, the site say's 20 for two. It's on the honor system as far as paying.
It's a great place to ride, there is plenty to see. Go to the park welcome center in Furnace Creek, literature there to look through and find what you want to see. Bring a camera. It is fun. The road in off of the 395 is a good time. Lots of curves, surprisingly. Unless of course you get stuck behind slow vehicles. Lots of off road stuff there too. They looked like decent dirt roads, but we were on our goldwing so couldn't try them out.