Fluid heat 5335CS Cracked water pump housing

I have a Fluidheat, hot water/steam cleaning machine. hadnt been fired up in eyars and upon doing so , the pump broke in pretty much half. This is the pump that FIrehawk industries says i need for 600 dollars. My question is,are there any other alternatives/can i attach a more powerful pump …it is direct driven on the backside of an electric motor. The front of the motor has a blower fan on it and a belt for the diesel pump (works perfectly) .