My first DF140 service was £98.......
The second one was £250
£120 of that was apparently labour according to the logsheet I have here.
As Hugh says, it's all in the owners handbook. I am about 4 to 5 months past 12months since the previous service and will be getting it serviced just before christmas as the 200hr service (yes, I have barely used the boat this year - weather and work issues

) which is likely to cost another £250 (great planning around christmas eh).
I am out of warranty now, but will continue to get the thing serviced (despite being stupid expensive) at the local authorised Suzuki dealer.
If you need any more info, let me know.
-Alex