What kind of numbers are you looking at in your contract?
Just going to throw this out there.......
15 miles of road x 4 times per year = 60 miles total. Assuming you can do it with one pass cutting and one pass spreading and if they're decent roads you should be able to get 1.5-2 miles done per hour ( really general numbers I have some roads I get 1.5 MPH on and some I can get 2.5-3 mph done on)
Lets be conservative and say 60 miles @ 1.5 miles per hour, your looking at 40 hours of grading + road time
I have no idea what you can get paid per hour or per mile in your location or what the possibility of picking up more work in your area with the machine would be, but when I read the numbers involved 2 things crossed my mind
A) I'd be looking for an older cat 12E or F in the 10-13K dollar range
or
B) Grading in other areas is far more lucrative than grading around here.
I know what you mean about knuckle busters, not sure if the controls are the same on the 12E's and F's but I have a Cat 120 S/N 60H (Same as the 12's I'm told) and the controls on it have some type of hydraulic assist, very minimal kickback in comparison to the older ones in my opinion. If they do kick back its because you have alot of force exherted on the lever and somthings got more pressure on it than it should have.
Anyway there are some distinct advantages to them and for the ammount of grading your talking about I wouldn't be afraid of one. I have a contract for 67 miles of road 5-6 times per year that I'm doing with mine, I'll guarantee its not as nice to run as the Deers and G models your looking at but I spent alot of 12 hour days in mine and its not horrible.
I've noticed some mid 80's champions in that less than 20k Price range, 720A's to be more specific, anyone have anything to say about them? I was getting the impression those are a good machine as well, might be one more thing to look at.