Before I directly respond, let me write that I am a huge proponent of track driving, I think it's a great way to safely enjoy your car, see what both it and you can do, and will make you a better driver (with proper instruction, natch).
However, I did just recently sell my M4 in anticipation of receiving the BW, and I had totally trashed my PS4S tires on that puppy with a rather aggressive weekend at VIR a few months ago. I'm an advanced driver, I used to instruct at HPDE and I can drive fast if I want to. I usually take it kind of easy, but that weekend I was really pushing it, and I toasted $2000 worth of tires. This affected resale, unfortunately, as no one wants a car with a set of tires trashed after only a few thousand miles. I have no one to blame but myself.
So there is that.
Not to mention the risk; your normal insurance is typically void on the track even if it's just a school, and track insurance is not cheap. Plus, of course, even if you are financially reimbursed, you have just dinged up your baby and no one wants that.
I'm actually in that dilemma right now... I've already signed up for and paid in advance for an Audi event coming up, and I'm debating whether or not to do it in my new BW.