I seem to be in the minority on this - but I get pretty good penetration (2 to3") with one of the lowes/home depot 48" pull behind aerators - $200 or less.. When the ground is moist, add about 100#, and go to town...
I just couldnt see spending $1k for a heavy duty model when it only gets used a 2 to 3 times a year..
Im sure a heavy duty model is errr more heavy duty, but im still getting nice holes in my yard with what I have..
just my thoughts - your mileage may vary..
Brian