Olde Thyme Aviation operates Scenic Biplane Rides in authentic restored antique biplanes at Boeing Field in Seattle.
Prices are $125 and up for two people. Parachutes included...unfortunately no aerobatics due to altitude restrictions.
They operate out of the Museum of Flight 10 AM to 5 PM on clear days. You can make an appointment on the day of the flight by calling 206-730-1412.
If you'd prefer to fly your own biplane they have a fully restored 1944 Stearman for sale for $125,000.