sorry to be dim...but its just heavier springs and fork oil isnt it?? Its not like 916 etc which have all the adjustment valves and bits. Therefore, why pay someone to do it if you can do it yourself and spend the dosh on getting it set up after? Not sure about later forks but early ones can even be done by me!!
I just replaced a fork seal and put a bit more oil in my (road-going) monster and the difference is stark! I was quoted £100 to do this job - took me a couple of hours and i have £80 left