911's were meant to be driven. Even though my 993 has been appreciating like crazy the last 18 months, I have to remember that I bought it to drive and enjoy. Not to park it and keep the kms down. Like Mooty on Rennlist says "Buy, drive, smile."
Now the GT cars have all seen large increases as well especially RS, RS 3.8, RS 4.0, GT2. I know that there aren't as many GT3 RS hitting the track anymore. If you do track it hats off to you. If you find that it is too much money to risk on the track you could build something purpose built for the track. Cayman track cars are readily available and you don't have to worry about values.
Oh and to keep on topic here is a pretty badass looking 07 Corvette for 35k CDN.
2007 Chevrolet Corvette 500HP Saanich, Victoria