Near nothing.
Boeing has some heavy-duty sales tax exemptions - and since the transfer of airliners to airlines happens over international waters, (airline crew, Boeing crew, and executives from both sides get on plane, fly over Pacific ocean, sign papers) the sale of the planes themselves is exempt. Tax revenues directly from Boeing are almost nil.
Boeing has spent the past 20 years in Washington state as the infamous 900lb gorilla, and their resistance to many development projects (and their associated taxes) has helped to transform the Puget Sound basin from a nice place to live into commuter hell. Now that the writing's on the wall, and they've sucked the blood out of the region, they're complaining about the mess they helped make, and using it as an excuse to wring even more concessions out of the state.
Fuck 'em. I hope whichever idiots take them next the best of luck - they'll need it.
And though you hold the keys to ruin of everything I see/With every prison blown to dust, my enemies walk free/Though all the kingdoms turn to sand and fall into the sea/ I'm mad about you I'm mad about you
