With me, running last year means nothing, it's not running now and there is no way to know if leaky carbs is it's only problem. Does the transmission work, charging system? What about all the bearings and bushings? Who knows? Also remember anything you can't do cost shop rate, setting up and syncing the carbs is likely a good example. As far as the parts that are on it; the exhaust is a few bends and a collector with an extremely cheap muffler, so you have used tires, clip ons, cafe seat and some type of shock (can't tell what they are), which are worth 50% (or less) of their original value.
The value, to me, would be a few hundred dollars in parts and the worth of a non running 350F in your area.
Personally, for $1500 or less, I would go and buy one of the thousands of newer 250/300cc bikes that are for sale (that 350F could never perform like they do), so I had something good to ride and save the other $1000+ for when a steal of a deal comes along on a vintage. I find the best deals on project bikes are in the dead of winter.