You just might luck out by contacting your nearest JD dealer, to see if they have couple (size you need) that was removed from a Zero turn where the buyer didn't want them on his tractor. Couple years ago, my JD dealer had a set 24" x 11" -12 for $125.00 each that that they removed from a Z950m.
Myself, I wouldn't spend the money(cost) for my Z710A, which has the 24" x 12" rims tires that may help some on the mowing impact.
Myself, I wouldn't spend the money(cost) for my Z710A, which has the 24" x 12" rims tires that may help some on the mowing impact.