BASH amps have been used by the major manufacturers like Klipsch, Velodyne and even SVS. Indigo Manufacturing has been making digital amps since the early 90's. The first time I saw them was their line of Blade car amps.
50 cents per watt (not 1/2 cent per watt as you have it noted) is not uncommon. The Behringer EP-4000 puts out an independently tested 1,600 watts and costs about $330. That's a little more than 20 cents per watt. I have never seen the PE BASH amp tested but O Audio's 500w BASH amp tested at 459.59 watts at 0.401% distortion. Most sub amps you see will have at 10% distortion rating so BASH amps sound extremely clean.