As I had mentioned to Dennis, we have 2 -24V mowers: B&D which we've had for years on its 2nd battery, and a Ryobi, which is a bit heavier and whose charge doesn't seem to last as long. I've seen the CMM1000 for sale at 389 on Amazon, plus, reconditioned ones at anywhere from 279-300.
it's true that 36V would be great, as it would hold a much better charge. But I'll bet they would be heavy. If guys were mowing, probably no problem. But my mother in law has some trouble negotiating the 24 V. However, I sure like the noise of them! quiet!