I don't know about your insurance company, but mine goes by current market value, specifically what similar bikes (or vehicles) are listed for in and around the area. Bluebook has little affect on it. My camaro had a bluebook of 900. It was a decent 87 350 TPI, but had 180K miles. It was totaled and I sat down with the adjuster. He showed me the bluebook and I was astonished how low it was. He then pulled up traderonline.com, ebay, and the local classifieds section of the paper. We agreed on $4200. After my deductible I received a check for $3700
Now on my 550, I have a stated value policy so they will pay out WAY more than $300, without having to sit down and negotiate.
If your insurance only pays out trade in value, that's a load of crap. I would be finding a new insurance company. I would buy any vehicle I could for trade in value!
How much extra do you pay for the coverage over liability and how much would it actually cost to replace or rebuild your 550? I'm not trying to be argumentative, I'd actually like to know.
I only carry liability even on my K1, which is definitely the most valuable of my current three bikes, because the cost of comprehensive (with $500 deductible figured in) seems like more than it's worth over the course of several years of riding. By putting the extra I would pay for comprehensive, let alone an agreed upon value, into my savings account, I have saved more than it would cost me to repair anything but a complete destruction of my bike.