You need to select the tracks which you want to export first. They then get rendered as .wav to a folder on the SD card. You can access either via usb or insert the SD into your computer. It's pretty straight forward.
I really really love the workflow of live mixing / bouncing the tracks on the Tascam and then only export the main tracks that I later want to eq for example. Do you get the idea? Not sure if I made it clear..
Be patient and you might get one for cheap :). I don't think their popularity will increase.. How is he utilising his device? What kind of music does he produce?