I have a used 2008 990 KTM Super Duke that I bought in Oct of 2009. I paid $6500 plus tax for it. Valves are shim on bucket, just like Jap stuff. I eventually replaced the right front Brembo rotor. It was difficult to tell if it was warped from new, or damaged by the previous owner. It cost me $200 to replace it. The fuel injectors got partially clogged. An $8 bottle of Lucas Oil Fuel injector Cleaner fixed that. Total cost of Maintainence, not counting tires and oil changes (3 quarts of oil, not 4): $208. Mods: Rear Spools (it was already drilled and tapped) $25, a tank pad/decal, front fork sliders, and frame plugs. So all in all, mods: aprox $100. So, a grand total of about $308 over 5 years. How many guys have owned a 919 for 5 years for less. And I have a much better motorcycle.
My 2009 KTM XC200W: Mods: hand guards, a skid plate, and a fly wheel weight. Maintainence/ repairs: a spark plug. But it doesn't get ridden all that much. When it comes to woods bikes, that thing is a masterpiece.
So much for "Expensive to own European motorcycles".
I had a WR450F for about a year and a half, several years ago. In a indiana, in the woods, that is WAAAAY too much bike. There might be a few pros that can ride those things in the woods, but the rest of us do much better on a 250. I don't know what kind of riding you guys do in Cali. A 450 might work out there. But for anything but a pretty straight dirt road, it's too much. The damn things will run almost 100 mph! I sold that bike and bought a WR250F. <That thing is s jewel. They're both great bikes. That 450 will wear you out.
The seat on a WR is only very slightly better than a 2X4.
Good luck. You're going to need it.