I deal with Progressive myself and they use several factors when putting a quote together for someone. Ont thing a lot of people don't think about is their credit rating? Sure they look at that to see how responsible you are, so a bad credit rating........not very responsible. Another couple of things they look at are, age, where you live, do you have any points on your license, have you had an accident within the last few years, and age bracket.
If you show them you credit rating is good, you're an older more responsible rider, and your license shows no points and no accidents I would remind them of this when getting them to give me a quote. Another item they like to see is more than one bike being insured on your policy and you are the only rider in the household. I know when I got my FJR I was given a quote that was twice as high as I was used to insuring my other bikes, when I called and wrote a letter asking why my rates were so high and pointing out I had several bikes on my policy with them, they actually came down quite a bit when they issued my first payment schedule.
If that doesn't work, do like the others have suggested and just do the liability insurance with a higher deductable.