When I stayed there with some Cyclewild guys a couple years ago, it was $9 I believe. Expensive for hiker/biker sites, but they're also the nicest hiker/biker sites I've ever seen
There's water at the hiker/biker sites.
There are showers, but they are up in the car camping end of the park. You can walk there from the hiker/biker sites.
As for the climb, it is pretty wicked, but it's really short. Maybe not quite half a mile. You could dismount and walk if you wanted. The more treacherous spot is actually a gravel road leading into the hiker/biker area. And by gravel, I mean, rock. Rocks like the size of your fist. Everyone in our group walked the bikes through that stretch, except me, cuz I wanted to show off my 26" wheeled LHT.