Charlie,
There are two things that have a major impact on the value:
(1) Do you have a clear title for the bike?
Some states make it nearly impossible to get a title for a vehicle that doesn't have one. Fortunately for you, Washington makes it easy to get one - see
https://www.washingtonlawhelp.org/resou ... my-vehicle - click the "How else can I get title". There's also Vermont.
(2) Does it run?
"Kicks over and has compression" doesn't tell much. Maybe it got stored because it stopped running and needs an expensive engine/transmission rebuild. Spend a weekend fiddling with it and see if you can get it to start.
The best way to to determine "fair market value" is to look at eBay. You will have to put the bikes you find there in your "watch list", and see what they actually sell for. You'll notice that the "no title, doesn't run" bikes sell for a lot less.
Dave