I have the parasound hca2003A (A is for the trigger"). I would say a fair price for this amp would be around 750.00 in good condition with box.
Its as close as you can get to the parasound 2200 mkII, which some would say is the best parasound amp made. The 2003 has gobs of power, current and amperage. Build quality is high and has plenty of weight to it. It can drive just about any speakers out there. I would charecterize it as being a tad on the warm side.