I think how much $ you spend on a zero turn, depends on how much you are going top use it, and how long you expect it to last.
I wanted a mower that would last many years, doing a LOT of cutting and would be useful in the winter too. Also I have bushes to mow under, so I wanted a front deck too. The front deck models ride a LOT better, so that helps my back issues, as they ride a lot better with the deck out front.
Anyway, I chose a Grasshopper 725-D and the D stands for diesel, as in Kubota diesel.
Also I opted for the electric lift on the deck,
That makes it REALLY easy to clean under the deck and when sharpening the blades is needed!!
I also bought the sno-blower option,
It's an amazing sno-blower! It works waaaay better than I expected it to, and throws the snow about 30'! It easily eats it way through deep snow too...
Anyway, I've owned/run different zero turns, but this one easily out shines the others I've used!
SR