Steering head bearings don't last long, also depending on how much dirt riding you will do. Average 15 000km on my bike. I think its a good idea to have them serviced every 10 000km, regardless.
Cost you a bit, but could save in the long run.
My bike has 44 000km on the clock and have not had any further issues. Also, I'm beginning to sence that it is only now run in. So anyone thinking of buying one, I would not sweat too much about the kilo's, as long as you ensure its been looked after by someone who knows.