Goes up pretty much every year, when I started going in 2008 it was €17/lap, it's now €29/lap.
It's so busy nowadays, you're lucky to get more than 20 laps in a weekend trip.
Nothing can beat the buzz though, when you're new to it, it's unbelievably scary. The faster you go the safer you are. I'm now at a pace where I rarely get passed thankfully, if I do it's locals in M3's and 911's.