I think one or two supersonic capable trainers or demilitarized jets have made it into civilian ownership!
But overall supersonic transport is very expensive when you can do 650 mph at one TENTH the dollars per flight hours in FUEL alone.
Supersonic Aerospace International (SAI), based in Nevada, USA, is developing a supersonic aircraft called Quiet Supersonic Transport (QSST). it’ll be ready for flight by 2014, and deliverable to customers by 2016. QSST (Quiet Supersonic Transport) could well be the future of high-speed passenger jets and the concept pictured above boasts some impressive figures. It promises to be 100 times quieter than the Concorde with a range of over 4000 nautical miles and a top speed of Mach 1.8, or 1,188 miles per hour. Check out the official site for More Information.

Originally posted by Stop-loss!I don't know if you are including commercial spacecraft in that question, but the Virgin Galactic craft will travel well over Mach 2 though I couldn't find the exact speed. But I can estimate it.
I was wondering if anyone knows of any aircraft that is currently being made for public transportation that can reach speeds of more then Mach 2 safely with efficiency and at a low cost.
Originally posted by AnteBellumWhether £121,000.00 is low cost or not is relative. It's too much for most of us, but it's far cheaper than the roughly $20 million others have been charged for a ride into space.
Virgin Galactic Link
The SpaceShip Two is able to hold six passengers and two crew, already 300 people have reportedly signed up at a cost of about £121,000.